#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;
	vector<ll> x(n + 1);
	rep(i, n + 1)
	{
		if (i == 0)x[i] = 0;
		else if (i == 1)x[i] = 1;
		else x[i] = (a * x[i - 1] + b * x[i - 2]) % mod;
	}
	co(x[n]);
	return 0;
}