#include<bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include<atcoder/modint>
#endif
using namespace std;
#define done(...) return pp(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;lin(__VA_ARGS__)
#define fo(i,...) for(auto[i,i##stop,i##step]=for_range<ll>(0,__VA_ARGS__);i<i##stop;i+=i##step)
#define defpp template<ostream&o=cout>void pp(const auto&...a){[[maybe_unused]]const char*c="";((o<<c<<a,c=" "),...);o<<'\n';}void epp(const auto&...a){pp<cerr>(a...);}
#define entry defpp void main();void main2();}int main(){my::io();my::main();}namespace my{
#define use_ml1000000007 using ml=atcoder::modint1000000007;
namespace my{
auto&operator<<(ostream&o,const atcoder::modint1000000007&x){return o<<(int)x.val();}
void io(){cin.tie(nullptr)->sync_with_stdio(0);cout<<fixed<<setprecision(15);}
using ll=long long;
template<class T>constexpr auto for_range(T s,T b){T a=0;if(s)swap(a,b);return array{a-s,b,1-s*2};}
void lin(auto&...a){(cin>>...>>a);}
constexpr auto pow(auto x,ll n,auto e){assert(n>=0);decltype(x)r=e;for(;n;x*=x,n>>=1)if(n&1)r*=x;return r;}
template<class...A>using pack_back_t=tuple_element_t<sizeof...(A)-1,tuple<A...>>;
}
namespace my{
template<class V>struct vec;
template<int D,class T>struct hvec_helper{using type=vec<typename hvec_helper<D-1,T>::type>;};
template<class T>struct hvec_helper<0,T>{using type=T;};
template<int D,class T>using hvec=hvec_helper<D,T>::type;
template<class V>struct vec:vector<V>{
  using vector<V>::vector;
  ll size()const{return vector<V>::size();}
};
template<class...A>requires(sizeof...(A)>=2)vec(const A&...a)->vec<hvec<sizeof...(A)-2,pack_back_t<A...>>>;
}
namespace my{
template<class T>struct matrix:vec<vec<T>>{
  ll H,W;
  matrix()=default;
  matrix(ll n):H(n),W(n){this->resize(n,vec<T>(n));}
  matrix(ll n,ll m,T x={}):H(n),W(m){this->resize(n,vec<T>(m,x));}
  matrix(const vec<vec<T>>&v):H(v.size()),W(v[0].size()){vector<vec<T>>::operator=(v);}
  auto&operator*=(const matrix&a){
    assert(W==a.H);
    matrix r(H,a.W);
    fo(i,H)fo(k,W)fo(j,a.W)r[i][j]+=(*this)[i][k]*a[k][j];
    swap(*this,r);
    return*this;
  }
  friend vec<T>operator*(const vec<T>&v,const matrix&a){
    assert(v.size()==a.H);
    vec<T>r(a.W);
    fo(i,a.H)fo(j,a.W)r[j]+=v[i]*a[i][j];
    return r;
  }
  auto pow(ll n)const{matrix e(H);fo(i,H)e[i][i]=1;return my::pow(*this,n,e);}
};
}
namespace my{entry
void main(){
  LL(a,b,N);
  if(N==0)done(2);

  use_ml1000000007
  matrix<ml>A({{2*a,1},{-a*a+b,0}});
  A=A.pow(N-1);
  pp((vec<ml>{2*a,2}*A)[0]);
}}