#include <bits/stdc++.h>
using namespace std;

int main()
{
  const long div = 1000000007;
  long a, b, n, prev = 0, current = 1;
  cin >> a >> b >> n;
  if (n < 2) {
    cout << n << endl;
    return 0;
  }
  for (int i = 2; i <= n; i++) {
    long next = (a * current % div + b * prev % div) % div;
    prev = current;
    current = next;
  }
  cout << current << endl;
}