#include <cstdio>const char *ans[] = { "", "2", "3", "4", "6", "8", "14", "20", "36", "60", "108", "188", "352", "632", "1182", "2192", "4116", "7712", "14602", "27596", "52488", "99880", "190746", "364724", "699252", "1342184", "2581428", "4971068", "9587580", "18512792", "35792568", "69273668", "134219796", "260301176", "505294128", "981706832", "1908881900", "3714566312", "7233642930", "14096303344", "27487816992", "53634713552", "104715443852", "204560302844", "399822505524", "781874936816", "1529755490574", "2994414645860", "5864062367252", "11488774559636", "22517998808028", "44152937528384", "86607686432616", "169947155749832", "333599974893066", "655069036708592", "1286742755471400", "2528336632928152", "4969489253251428", "9770521225481756", "19215358428046176", "37800705069076952", "74382032589917286", "146402730743793240", "288230376218822676", "567592125344909792", "1117984489446008100", "2202596307308603180", "4340410370537249376", "8555011744329310568", "16865594582168158776", "33256101992039755028", "65588423374144427520", "129379903640264252432", "255263053129946213628", "503719091506096386000", "994182417449857925988", "1962541914958813595480", "3874762242361630560584", "7651429238067273257636", "15111572745196608608736", "29850020237398254541372", "58971991200740435635128", "116522970565265462622284", "230271584688553159320640", "455125014443154512836736", "899665726224942596211834", "1778649481731868223403824", "3516875111606393874082104", "6954719321827979072466992", "13754889325393505126886888", "27207473390887478569212080", "53823479968930342047363612", "106489465744978948424601736", "210713198176236437615684502", "416990329022443882071306032", "825293359523589782053586452", "1633570361118852321516370112", "3233802551602631768613564510", "6402275758728431320863954440", "12676506002282305273966813560", "25101992083727314881122835752", "49711788244244312331578299104", "98458299046852769048287627604", "195023169265881489687952047216", "386331611498127055694887910816", "765373947307610289650832640428", "1516441839525358536369887946620", "3004801422763210599978631833324", "5954468874466545445562495790392", "11800674678488244937831101073320", "23388724587994719047437144527184", "46359793379775247326679383075720", "91899059443094294310274271313632", "182185854685432549633664238154388", "361203259724161921984730179715792", "716178877039286571937226883560136", "1420115380112089607803222068775440", "2816161008018889566122139977741610", "5584991578928217953377340589419840", "11076899964874298950472756384394096", "21970710674130840874443091905460412", "43581245763439864704271075822418628", "86453853384384772221385860815359904", "171513289778698822347359669251676364", "340282366920938463463374607432841960", "675163426430433459325928830880124772", "1339694357956450643556592942644756740", "2658455991569831745951729308703655956", "5275695611177340518812009553920329208", "10470226674490414260695322445190464848", "20780602560057310745854937858428593068", "41246347505568298602180157048520378688", "81872449183985194216751785246741247480", "162522921514478072103011558419573447362", "322638096043556469061569998678782313456", "640531514204119460639110642704017464896", "1271712203383361264914217510985878279312", "2524993795123485410051347057690049705196", "5013656744273971030021519395829217964476", "9955689820772599616765449883295070035792", "19770164183094524061645140314627802588360", "39261875349525744967509089798616374641566", "77974633561295885110264749205064201070608", "154866286100907105149586393331210545684640", "307596485496974112297044389967563621789280", "610979320507688305247618615229857433659928", "1213645997198945477090379225730018992974632", "2410891372814121420706691769110172551043576", "4789421787603892218316395870635889719405192", "9514984618039732540388824989224065984802392", "18903942949747812994149483039066160746791348", "37559149808051575817323812076721756642186328", "74627330337566529728537828467976893403203520", "148285474566852974655407315759216714355819012", "294657588171553007702355813047637705631211792", "585537514956291233254683360745074363363398272", "1163615953288935444429685376366467372337525912", "2312502590713453984499505143303674444484623350", "4595917098524851944036744756969556756141356944", "9134385233318143238773037760263141478133217760", "18155299842619912027374966866040782852869039880", "36086460181009948597621862646400045288144250378", "71730141709492167764598028599572172743849449964", "142585525593258821288164403409535407179327231856", "283442741785387232621320694829825022343140844768", "563470510778179438343589391356919699849476387954", "1120192871726680081018393165195713931233289613780", "2227050114028042542024662717370129232083156792840", "4427744605404865645682169434028029029963535278712", "8803398097804968166121019455218235528211042556608", "17503832475167772961878049926333028727986701771240", "34804132014577781121873797396378765720142785251572", "69205904121472582115171018205848499982782655445432", "137616338080629387424420531344632680926299347837224", "273659918011765867563990540562555211360489915477264", "544210064227943486632935735831700760213360501424984", "1082270862193424334998832646292591237882846863727672", "2152381377620630419042622232621052334535814146041928", "4280713801301365526140634154051142971002064587105036", "8513864115921604768657483491045829028944628067075024", "16933652385258440423849138421550377719544078698161352", "33681220678371183700183451159764378093657785928217352", "66994340584301152277960525777062696576839338775389104", "133260481814425118118117132822590799429573303217695912", "265080309771396991716038404696269696625944067349357216", "527310293631273585671689299717867247715622140108028380", "1048980904977720715881649302006628746006409666521403328", "2086802438625891211381578930693011657632785006129600300", "4151522311763677753859649089423059799107096162076887640", "8259344388666685215573407136008056238330110689538391304", "16432203495776651214229815243999126743723443571895378308", "32693238205138962311644736579619242597153717881060460052", "65047686377064049366173983660183071669454460564394140032", "129424778049209912656408029345304752522876033263109412128", "257522122477402287747109309670058109378936566842082759104", "512416468194831082762105259038977425039258906059695130428", "1019630738743014134227133307323072717336423219405325403112", "2028962177094684691340861227706689272377840591409360830892", "4037532774520076069200909779751664830457796466790936772116", "8034690221294951377709810461712151265612156127202437685648"};int main(){ int n; while (scanf("%d", &n) != EOF && n != 0) { puts(ans[n]); } return 0;}
