#include <iostream>#include <cmath>#include <stdio.h>#include <algorithm>#define max(x,y) ((x)>(y)?(x):(y))#define min(x,y) ((x)<(y)?(x):(y))#define INF 1000000000using namespace std;struct Point{ double x,y;};struct Seg{ Point s,t;};struct Node{ double y1,y2;};Point p[105];Seg a[105];Node Y[105];int yNum=0;int n;double minx,maxx;bool cmp(Node a,Node b){ if(a.y1==b.y1) return a.y2<b.y2; return a.y1<b.y1;}int cal(){int ans=0,i;double dx;int temp,pre,t1,t2;for(dx=minx;dx<maxx;dx+=1){yNum=0;for(i=0;i<n;i++) if(a[i].s.x<=dx&&a[i].t.x>=dx+1){Y[yNum].y1=a[i].s.y+(a[i].t.y-a[i].s.y)*(dx-a[i].s.x)/(a[i].t.x-a[i].s.x);Y[yNum++].y2=a[i].s.y+(a[i].t.y-a[i].s.y)*(dx+1-a[i].s.x)/(a[i].t.x-a[i].s.x);}sort(Y,Y+yNum,cmp);temp=0,pre=-INF;for(i=0;i<yNum-1;i+=2){ t1=(int)ceil(max(Y[i+1].y1,Y[i+1].y2));t2=(int)floor(min(Y[i].y1,Y[i].y2));temp+=t1-t2;if(t2<=pre) temp-=pre-t2;pre=t1;}if(temp>0) ans+=temp;}return ans;}int main(){ while(scanf("%d",&n),n) { minx=INF;maxx=-INF;int i; for(i=0;i<n;i++) { scanf("%lf%lf",&p[i].x,&p[i].y);maxx=max(maxx,p[i].x);minx=min(minx,p[i].x); } for(i=0;i<n;i++) { if(p[i].x<p[(i+1)%n].x) a[i].s=p[i],a[i].t=p[(i+1)%n]; else a[i].s=p[(i+1)%n],a[i].t=p[i]; } printf("%dn",cal()); } return 0;}
