View Code of Problem 80

#include<stdio.h> 
#include<string.h>
#include<math.h>
int main(){
    int i,n,count;
    while(~scanf("%d",&n)){
    	if(n==0) break;
        int s=0;
        for(i=2;i<=n;i++)
          s=(s+3)%i;
		printf("%d\n",s+1);
        
	}
    return 0; 
     
}