#include <stdio.h>
#define M 1000000007
int main(){
  int x0, x1, x2, a, b, n, i, p, q, r;
  x0 = 0;
  x1 = 1;
  scanf("%d %d %d", &a, &b, &n);
  for (i=2; i<=n; i++){
    q = x1;
    x2 = a*x1+b*x0;
    x1 = x2;
    x0 = q;
    
  } 
  r = x2 % M;
  printf("%d", r);
  return 0;
}