#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = long long;
using std::cout;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

struct matrix {
	std::vector<std::vector<i64>> A;

	const int MOD = 1e9 + 7;
	
	matrix(const int & n) {
		A.resize(n, std::vector<i64>(n));
	}

	matrix operator*(matrix B) {
		const int n = A.size();

		matrix C(n);
		for(int i = 0; i < n; i++) {
			for(int j = 0; j < n; j++) {
				for(int k = 0; k < n; k++) {
					(C[i][j] += A[i][k] * B[k][j] % MOD) %= MOD;
				}
			}
		}
		return C;
	}

	void pow(i64 n) {
		int d = A.size();

		matrix ret(d);
		for(int i = 0; i < d; i++) ret[i][i] = 1;
		while(n) {
			if(n & 1) ret = ret * (*this);
			(*this) = (*this) * (*this);
			n >>= 1;
		}
		(*this) = ret;
	}
	void operator=(matrix B) {
		A.swap(B.A);
	}
	std::vector<i64> & operator[](const int & i) {
		return A[i];
	}
};

int main() {
	i64 a, b, n; scanf("%lld%lld%lld", &a, &b, &n);
	if(n == 0) {
		printf("0\n");
		return 0;
	}
	if(n == 1) {
		printf("1\n");
		return 0;
	}
	
	matrix A(2);
	A[0][0] = a;
	A[0][1] = b;
	A[1][0] = 1;
	A[1][1] = 0;
	A.pow(n - 1);

	printf("%lld\n", A[0][0]);
	return 0;
}