//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <unordered_map>
#include <climits>
#include <set>
#include <unordered_set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <queue>
#include <random>
#include <complex>
#include <regex>
#include <locale>
#include <random>
#include <type_traits>

using namespace std;

#define SHOW_VECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOW_MAP(v){std::cerr << #v << endl; for(const auto& xxx: v){std::cerr << xxx.first << " " << xxx.second << "\n";}}

using LL = long long;

//------------------------------------------
//------------------------------------------

template<class T>
using Matrix = vector<vector<T>>;

template<class T>
Matrix<T> mat_add(Matrix<T> A, Matrix<T> B, const LL MOD) {
    int m = A.size();
    int n = B[0].size();
    Matrix<T> C(m, vector<T>(n));
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            C[i][j] = A[i][j] + B[i][j];
            C[i][j] %= MOD;
        }
    }
    return C;
}

template<class T>
Matrix<T> mat_sub(Matrix<T> A, Matrix<T> B, const LL MOD) {
    int m = A.size();
    int n = B[0].size();
    Matrix<T> C(m, vector<T>(n));
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            C[i][j] = A[i][j] - B[i][j] + MOD;
            C[i][j] %= MOD;
        }
    }
    return C;
}

template<class T>
Matrix<T> mat_mul(Matrix<T> A, Matrix<T> B, const LL MOD) {
    int m = A.size();
    int l = B.size();
    int n = B[0].size();
    Matrix<T> C(m, vector<T>(n));
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < l; k++) {
                C[i][j] += A[i][k] * B[k][j];
                C[i][j] %= MOD;
            }
        }
    }
    return C;
}

template<class T>
Matrix<T> mat_pow_mod(Matrix<T> A, LL p, const LL MOD) {
    Matrix<T> ret(A.size(), vector<T>(A.size(), 0));
    for (int i = 0; i < A.size(); i++) ret[i][i] = 1;
    while (p > 0) {
        if (p & 1) ret = mat_mul(ret, A, MOD);
        A = mat_mul(A, A, MOD);
        p >>= 1;
    }
    return ret;
}

constexpr LL mod = 1e9 + 7;

int main() {

    LL a, b, n;
    cin >> a >> b >> n;

    Matrix<LL> A(2, vector<LL>(2));
    A[0][0] = a;
    A[0][1] = b;
    A[1][0] = 1;
    A[1][1] = 0;

    if (n == 0) {
        cout << 0 << endl;
        return 0;
    } else if (n == 1) {
        cout << 1 << endl;
        return 0;
    }

    Matrix<LL> B(2, vector<LL>(1));
    B[0][0] = 1;
    B[0][1] = 0;

    auto ans = mat_mul(mat_pow_mod(A, n - 1, mod), B, mod);
    cout << ans[0][0] << endl;

    return 0;
}