#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#define popcount __builtin_popcount
using namespace std;
using ll=long long;
typedef pair<int, int> P;
const ll MOD=1e9+7;
vector<vector<ll>> matrixmul(int l, int m, int n, vector<vector<ll>> a, vector<vector<ll>> b){
	vector<vector<ll>> c(l, vector<ll>(n));
	for(int i=0; i<l; i++){
		for(int k=0; k<m; k++){
			for(int j=0; j<n; j++){
				(c[i][j]+=a[i][k]*b[k][j])%=MOD;
			}
		}
	}
	return c;
}
vector<vector<ll>> matrixpow(int n, vector<vector<ll>> a, ll k){
	vector<vector<ll>> ap=a, ans(n, vector<ll>(n));
	for(int i=0; i<n; i++) ans[i][i]=1;
	while(k){
		if(k&1) ans=matrixmul(n, n, n, ap, ans);
		ap=matrixmul(n, n, n, ap, ap);
		k>>=1;
	}
	return ans;
}
int main()
{
    ll a, b, n; cin>>a>>b>>n;
    vector<vector<ll>> mat(2, vector<ll>(2));
    mat[0][0]=a, mat[0][1]=b, mat[1][0]=1, mat[1][1]=a;
    auto matp=matrixpow(2, mat, n);
    cout<<2*matp[0][0]%MOD<<endl;
    return 0;
}