//GIVE ME AC!!!!!!!!!!!!!!!!!
//#pragma GCC target("avx")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define floatset() fixed<<setprecision(15)
#define all(n) n.begin(),n.end()
#define rall(n) n.rbegin(),n.rend()
#define rep(i, s, n) for (ll i = s; i < (ll)(n); i++)
#define pb push_back
#define eb emplace_back
#define max_(a) *max_element(all(a))
#define min_(a) *min_element(all(a))
#define INT(...) int __VA_ARGS__;scan(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;scan(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;scan(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;scan(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;scan(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;scan(__VA_ARGS__)
using namespace std;
using vl=vector<ll>;
using vi=vector<int>;
using vs=vector<string>;
using vc=vector<char>;
using vvl=vector<vl>;
using P=pair<ll,ll>;
using vvc=vector<vc>;
using vd=vector<double>;
using vp=vector<P>;
using vb=vector<bool>;
const int dx[8]={1,0,-1,0,1,-1,-1,1};
const int dy[8]={0,1,0,-1,1,1,-1,-1};
const ll inf=2e18;
const ll MOD=1000000007;
const ll mod=998244353;
const double pi=acos(-1);
template<typename T1,typename T2 >
ostream &operator<<(ostream&os,const pair<T1,T2>&p) {
  os<<p.first<<" "<<p.second;
  return os;
}
template<typename T1,typename T2>
istream &operator>>(istream&is,pair<T1,T2>&p) {
  is>>p.first>>p.second;
  return is;
}
template<typename T>
ostream &operator<<(ostream&os,const vector<T>&v) {
  for(int i=0;i<(int)v.size();i++) {
    os<<v[i]<<(i+1!=v.size()?" ":"");
  }
  return os;
}
template<typename T>
istream &operator>>(istream&is,vector<T>&v) {
  for(T &in:v)is>>in;
  return is;
}
void scan(){}
template<class Head,class... Tail>
void scan(Head&head,Tail&... tail) {
  cin>>head;
  scan(tail...);
}
template<class T>
void print(const T &t) { cout << t << '\n'; }
template<class Head, class... Tail>
void print(const Head &head, const Tail &... tail) {
  cout << head << ' ';
  print(tail...);
}
template<class... T>
void fin(const T &... a) {
  print(a...);
  exit(0);
}
template<typename T>
ll sum_(vector<T>&v){
  ll res=0;
  for(auto &e:v)res+=e;
  return res;
}
template<typename T1,typename T2>
inline bool chmax(T1&a,T2 b){return a<b&&(a=b,true);}
template<typename T1,typename T2>
inline bool chmin(T1&a,T2 b){return a>b&&(a=b,true);}
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using mint = atcoder::modint1000000007;
#endif
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(){
    return (A.size());
  }
  size_t width(){
    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 E(size_t n){
    Matrix mat(n);
    for(int i=0;i<n;i++)mat[i][i]=1;
    return (mat);
  }
  Matrix &operator+=(Matrix&B){
    size_t n=height(),m=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-=(Matrix&B){
    size_t n=height(),m=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*=(Matrix&B) {
    size_t n=height(),m=B.width(),p=width();
    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]+=(*this)[i][k]*B[k][j];
    A.swap(C);
    return (*this);
  }
  Matrix &operator^=(long long k){
    Matrix B=Matrix::E(height());
    while(k>0){
      if(k&1)B*=*this;
      *this*=*this;
      k>>=1LL;
    }
    A.swap(B.A);
    return (*this);
  }
  Matrix operator+(Matrix&B){
    return (Matrix(*this)+=B);
  }
  Matrix operator-(Matrix &B){
    return (Matrix(*this)-=B);
  }
  Matrix operator*(Matrix&B){
    return (Matrix(*this)*=B);
  }
  Matrix operator^(long long k){
    return (Matrix(*this)^=k);
  }
};
int main(){
  LL(a,b,n);
  Matrix<mint>x(2),y(2,1);
  y[0][0]=1,y[1][0]=0;
  x[0][0]=a,x[0][1]=b,x[1][0]=1;
  x^=(n-1);
  y*=x;
  fin(y[0][0].val());
}