View Code of Problem 80

#include <stdio.h>
#include <stdlib.h>
#include<ctype.h>
#include<string.h>
#include<math.h>
int ysfdg(int sum, int value, int n)
{
	if (n == 1)
		return (sum + value - 1) % sum;
	else
		return (ysfdg(sum - 1, value, n - 1) + value) % sum;
}
int main()
{
	int sum, n, i,k;

	while (scanf("%d", &sum) != EOF)
	{
		if (sum == 0)
			break;
		
		k = ysfdg(sum, 3, sum);
			printf("%d\n",k+1);
	}
	
	return 0;
}