//c

//https://github.com/WEIZIBIN/acm/blob/master/hdu1005.c
#include <stdio.h>
int main()
{
int i, result, a, b, j;
long n;
int f[50] = {0};
f[1] = 1;
f[2] = 1;
while(scanf("%d%d%d", &a, &b, &n) != EOF)
{
for (j = 3; j < 50; ++j)
{
f[j] = (a * f[j - 1] + b * f[j - 2]) % 7;
if (f[j] == 0 && f[j - 1] == 0)
break;
}

	if(n == 0)
		break;
	else
		printf("%d\n", f[n % 49]);
}
return 0;

}

hdu1005