#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <sstream>
#include <map>
#include <queue>
#define rep(i,n) for(int i = 0; i < n; i++)
#define rep1(i,n) for(int i = 1; i <= n; i++)
#define co(x) cout << x <<endl
#define cs(x) cout << x <<" "
#define ALL(a) (a).begin(),(a).end()
typedef long long ll;
using namespace std;
ll mod = 1e9 + 7;

int main()
{
	ll a, b, n;
	cin >> a >> b >> n;
	ll x;
	if (n == 0)x = 0;
	else if (n == 1)x == 1;
	else
	{
		ll x_last = 1;
		ll x_last2 = 0;
		rep(i, n - 1)
		{
			x = (a * x_last + b * x_last2) % mod;
			x_last2 = x_last;
			x_last = x;
		}
	}
	co(x);
	return 0;
}