#include"bits/stdc++.h"
using namespace std;
#define REP(k,m,n) for(int (k)=(m);(k)<(n);(k)++)
#define rep(i,n) REP((i),0,(n))
using ll = long long;

using vec = vector<ll>;
using mat = vector<vec>;
constexpr ll MOD = 1000000007;// 10^9+7

//A*Bの計算
mat mul(const mat& A, const mat& B) {
	mat C(A.size(), vec(B[0].size()));
	rep(i, A.size())rep(k, B.size())rep(j, B[0].size())
		C[i][j] = (C[i][j] + A[i][k] * B[k][j]) % MOD;
	return C;
}

//A^Kの計算
mat pow(mat A, ll N) {
	mat B(A.size(), vec(A.size()));
	rep(i, A.size())B[i][i] = 1;
	while (N > 0) {
		if (N & 1)B = mul(B, A);
		A = mul(A, A);
		N >>= 1;
	}
	return B;
}

int main()
{
	ll a, b, n;
	cin >> a >> b >> n;
	mat A = {
		{(a*a + b) % MOD, (a*b) % MOD},
		{a, b},
	};
	A = pow(A, n / 2);
	cout << A[(n + 1) % 2][0] << endl;
	return 0;
}