#include <iostream>
#include <vector>
using namespace std;

typedef vector<vector<int64_t>> Matrix;
// 行列の乗算(mod)
Matrix ModMultiMatrix(const Matrix &a, const Matrix &b, int64_t mod)
{
  Matrix c(a.size(), vector<int64_t>(b.at(0).size()));
  for(int i = 0; i < a.size(); i++)
  {
    for(int j = 0; j < b.size(); j++)
    {
      for(int k = 0; k < b.at(0).size(); k++)
      {
        c.at(i).at(k) += a.at(i).at(j) * b.at(j).at(k);
        c.at(i).at(k) %= mod;
      }
    }
  }
  return c;
}
// 行列の累乗(mod)
Matrix ModPowerMatrix(Matrix a, int64_t n, int64_t mod)
{
  Matrix b(a.size(), vector<int64_t>(a.size()));
  for(int i = 0; i < a.size(); i++) b.at(i).at(i) = 1;
  while(n > 0)
  {
    if(n & 1) b = ModMultiMatrix(b, a, mod);
    a = ModMultiMatrix(a, a, mod);
    n >>= 1;
  }
  return b;
}

int main()
{
  int64_t A, B, N;
  cin >> A >> B >> N;
  
  if(N == 0)
  {
    cout << 0 << endl;
    return 0;
  }
  
  int64_t mod = 1000000007;
  Matrix mat(2, vector<int64_t>(2));
  mat.at(0).at(0) = A;
  mat.at(0).at(1) = B;
  mat.at(1).at(0) = 1;
  mat = ModPowerMatrix(mat, N - 1, mod);
  
  Matrix F(2, vector<int64_t>(1));
  F.at(0).at(0) = 1;
  Matrix ans = ModMultiMatrix(mat, F, mod);
  cout << ans.at(0).at(0) << endl;
  return 0;
}