#include "bits/stdc++.h"
#define ALL(obj) (obj).begin(),(obj).end()
#define RALL(obj) (obj).rbegin(),(obj).rend()
#define REP(i, n) for(int i = 0; i < int(n); i++)
#define FOR(i,n,m) for(int i = int(n); i < int(m); i++)
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = MOD - 1;
const ll LLINF = 4e18;

struct mint {
private:
    ll x;
public:
    mint(ll x = 0) :x(x%MOD) {}
    mint& operator+=(const mint a) {
        if ((x += a.x) >= MOD) x -= MOD;
        return *this;
    }
    mint& operator-=(const mint a) {
        if ((x += MOD - a.x) >= MOD) x -= MOD;
        return *this;
    }
    mint& operator*=(const mint a) {
        (x *= a.x) %= MOD;
        return *this;
    }
    mint operator+(const mint a) const {
        mint res(*this);
        return res += a;
    }
    mint operator-(const mint a) const {
        mint res(*this);
        return res -= a;
    }
    mint operator*(const mint a) const {
        mint res(*this);
        return res *= a;
    }
    friend ostream& operator<<(ostream& os, const mint& n) {
        return os << n.x;
    }
};

template< class T >
struct Matrix {
    vector< vector< T > > A;

    Matrix() {}

    Matrix(size_t n, size_t m) : A(n, vector< T >(m, 0)) {}

    Matrix(size_t n) : A(n, vector< T >(n, 0)) {};

    size_t height() const {
        return (A.size());
    }

    size_t width() const {
        return (A[0].size());
    }

    inline const vector< T > &operator[](int k) const {
        return (A.at(k));
    }

    inline vector< T > &operator[](int k) {
        return (A.at(k));
    }

    static Matrix I(size_t n) {
        Matrix mat(n);
        for (int i = 0; i < n; i++) mat[i][i] = 1;
        return (mat);
    }

    Matrix &operator+=(const Matrix &B) {
        size_t n = height(), m = width();
        assert(n == B.height() && m == B.width());
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                (*this)[i][j] += B[i][j];
        return (*this);
    }

    Matrix &operator-=(const Matrix &B) {
        size_t n = height(), m = width();
        assert(n == B.height() && m == B.width());
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                (*this)[i][j] -= B[i][j];
        return (*this);
    }

    Matrix &operator*=(const Matrix &B) {
        size_t n = height(), m = B.width(), p = width();
        //assert(p == B.height());
        vector< vector< T > > C(n, vector< T >(m, 0));
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                for (int k = 0; k < p; k++)
                    C[i][j] = (C[i][j] + (*this)[i][k] * B[k][j]);
        A.swap(C);
        return (*this);
    }

    Matrix operator+(const Matrix &B) const {
        return (Matrix(*this) += B);
    }

    Matrix operator-(const Matrix &B) const {
        return (Matrix(*this) -= B);
    }

    Matrix operator*(const Matrix &B) const {
        return (Matrix(*this) *= B);
    }

    friend ostream &operator<<(ostream &os, Matrix &p) {
        size_t n = p.height(), m = p.width();
        for (int i = 0; i < n; i++) {
            os << "[";
            for (int j = 0; j < m; j++) {
                os << p[i][j] << (j + 1 == m ? "]\n" : ",");
            }
        }
        return (os);
    }
    // 行列式
    T determinant() {
        Matrix B(*this);
        assert(width() == height());
        T ret = 1;
        for (int i = 0; i < width(); i++) {
            int idx = -1;
            for (int j = i; j < width(); j++) {
                if (B[j][i] != 0) idx = j;
            }
            if (idx == -1) return (0);
            if (i != idx) {
                ret *= -1;
                swap(B[i], B[idx]);
            }
            ret *= B[i][i];
            T vv = B[i][i];
            for (int j = 0; j < width(); j++) {
                B[i][j] /= vv;
            }
            for (int j = i + 1; j < width(); j++) {
                T a = B[j][i];
                for (int k = 0; k < width(); k++) {
                    B[j][k] -= B[i][k] * a;
                }
            }
        }
        return (ret);
    }
};

//pow
template<typename T, typename U>
T pow(T k, U n, T unity = 1) {
    while (n > 0) {
        if (n & 1) {
            unity *= k;
        }
        k *= k;
        n >>= 1;
    }
    return unity;
}

int main() {
    int a, b, n; cin >> a >> b >> n;
    Matrix<mint> mat(2,2);
    if (n >= 2) {
        mat[0][0] = a; mat[0][1] = b;
        mat[1][0] = 1; mat[1][1] = 0;
        auto m = pow(mat,n - 1,Matrix<mint>::I(2));
        std::cout << m[0][0] << endl;
    }
    else {
        std::cout << n << endl;
    }
}