#include <stdio.h>#include <limits.h>#include <string.h>#define N 10001int sequence[N],line,time,result,answer[N / 2 + 2][2];int find(){ memset(sequence,0,sizeof(sequence));int k,time1,p,q,i,aim,kmax = 0;for (k = 1;k <= 10000;k ++){aim = line;time1 = time;p = 0;q = k - 1;while (time1 > 0){time1 --;i = (p + q) / 2;if (i == aim && time1 > 0)break;if (i == aim && time1 == 0){sequence[k] = 1;kmax = k;break;}if (line < i)q = i - 1;elsep = i + 1;}}result = 0;memset(answer,0,sizeof(answer));i = 1;while(i <= kmax){if (sequence[i] == 1){result ++;answer[result][0] = i;while (sequence[i] == 1)i ++;answer[result][1] = i - 1;}elsei ++;}printf("%dn",result);for (i = 1;i <= result;i ++)printf("%d %dn",answer[i][0],answer[i][1]);return 0;}int main(){scanf("%d%d",&line,&time);find();return 0;}
