#include<iostream>
using namespace std;

long a,b,i,T,c=(1000000007),K;

int power(long T)
{
 if(T==0)
 {
  return 1;   
 }    
 else
 {
  if(T%2==0)   
  return ((power(T/2)%c)*(power(T/2)%c))%c;
  else
  return (((K%c)*(power(T/2)%c)%c)*(power(T/2)%c))%c;    
 }    
}

int main()
{
 cin>>a>>b;
 
 cin>>T;   
 
 long power1;   
 K=(a+b)/2; 
    
 power1=power(T);   
    
 cout<<power1;
    
 return 0;   
}