// Template
#define FORESTED
#include "bits/stdc++.h"
#define rep_override(x, y, z, name, ...) name
#define rep2(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep3(i, l, r) for (int i = (int)(l); i < (int)(r); ++i)
#define rep(...) rep_override(__VA_ARGS__, rep3, rep2)(__VA_ARGS__)
#define per(i, n) for (ll i = (ll)(n) - 1; i >= 0; --i)
#define all(x) (x).begin(), (x).end()
using namespace std;
using ll = long long;
constexpr int inf = 1001001001;
constexpr ll INF = 3003003003003003003LL;
template <typename T>
inline bool chmin(T &x, const T &y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}
template <typename T> 
inline bool chmax(T &x, const T &y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
struct IOSET {
    IOSET() {
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(10);
    }
} ioset;
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
    for (T &element : vec) is >> element;
    return is;
}
template <typename T>
vector<T> operator--(vector<T> &vec) {
    for (T &element : vec) --element;
    return vec;
}

// Matrix
template <typename T>
class Matrix {
    int h, w;
    std::vector<std::vector<T>> vec;
    
public:
    Matrix(int h_, int w_) : h(h_), w(w_), vec(h_, std::vector<T>(w_, T(0))) {}
    
    const std::vector<T> &operator[](int x) const {
        return vec.at(x);
    }
    
    std::vector<T> &operator[](int x) {
        return vec.at(x);
    }
    
    Matrix &operator+=(const Matrix<T> &x) {
        assert(h == x.h && w == x.w);
        for (int i = 0; i < h; ++i) {
            for (int j = 0; j < w; ++j) {
                vec[i][j] += x.vec[i][j];
            }
        }
        return *this;
    }
    
    Matrix &operator-=(const Matrix<T> &x) {
        assert(h == x.h && w == x.w);
        for (int i = 0; i < h; ++i) {
            for (int j = 0; j < w; ++j) {
                vec[i][j] -= x.vec[i][j];
            }
        }
        return *this;
    }
    
    Matrix &operator*=(const Matrix<T> &x) {
        assert(w == x.h);
        std::vector<std::vector<T>> res(h, std::vector<T>(x.w, T(0)));
        for (int i = 0; i < h; ++i) {
            for (int j = 0; j < x.w; ++j) {
                for (int k = 0; k < w; ++k) {
                    res[i][j] += vec[i][k] * x.vec[k][j];
                }
            }
        }
        vec.swap(res);
        return *this;
    }
    
    Matrix operator+(const Matrix<T> &x) const {
        return Matrix(*this) += x;
    }
    
    Matrix operator-(const Matrix<T> &x) const {
        return Matrix(*this) -= x;
    }
    
    Matrix operator*(const Matrix<T> &x) const {
        return Matrix(*this) *= x;
    }
    
    Matrix pow(long long x) const {
        assert(x >= 0 && h == w);
        Matrix<T> a(h, h), b(*this);
        for (int i = 0; i < h; ++i) a[i][i] = T(1);
        while (x) {
            if (x & 1) {
                a *= b;
            }
            b *= b;
            x >>= 1;
        }
        return a;
    }
};

// Mod-Int
template <int MOD>
struct ModInt {
    static_assert(MOD >= 1);
    
    long long val;
    
    ModInt() = default;
    
    ModInt(long long x) : val(x % MOD + (x < 0 ? MOD : 0)) {}
    
    ModInt<MOD> &operator+= (const ModInt<MOD> &x) {
        if ((val += x.val) >= MOD) val -= MOD;
        return *this;
    }
    
    ModInt<MOD> &operator-= (const ModInt<MOD> &x) {
        if ((val -= x.val) < 0) val += MOD; 
        return *this;
    }
    
    ModInt<MOD> &operator*= (const ModInt<MOD> &x) {
        (val *= x.val) %= MOD; return *this;
    }
    
    ModInt<MOD> operator+ (const ModInt<MOD> &x) const {
        return ModInt(*this) += x;
    }
    
    ModInt<MOD> operator- (const ModInt<MOD> &x) const {
        return ModInt(*this) -= x;
    }
    
    ModInt<MOD> operator* (const ModInt<MOD> &x) const {
        return ModInt(*this) *= x;
    }
    
    ModInt<MOD> pow(long long t) const {
        assert(t >= 0);
        ModInt<MOD> res(1), now(*this);
        while (t) {
            if (t & 1) res *= now;
            now *= now;
            t >>= 1;
        }
        return res;
    }
    
    ModInt<MOD> inv() const {
        return pow(MOD - 2);
    }
    
    ModInt<MOD> &operator/= (const ModInt<MOD> &x) {
        return *this *= x.pow(MOD - 2);
    }
    
    ModInt<MOD> operator/ (const ModInt<MOD> &x) const {
        return ModInt(*this) /= x;
    }
    
    friend std::istream &operator>> (std::istream &is, ModInt<MOD> &x) {
        long long a;
        is >> a;
        x = ModInt<MOD>(a);
        return is;
    }
    
    friend std::ostream &operator<< (std::ostream &os, const ModInt<MOD> &x) {
        os << x.val;
        return os;
    }
};

constexpr int mod = 1000000007;
using mint = ModInt<mod>;

// Main
int main() {
    int a, b, n;
    cin >> a >> b >> n;
    Matrix<mint> mat(2, 2);
    mat[0][0] = mint(a);
    mat[0][1] = mint(b);
    mat[1][0] = mint(1);
    Matrix<mint> ans = mat.pow(n);
    cout << ans[1][0] << "\n";
}