#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
#define mod 1000000007
long long int power(long long int x, unsigned long long int y,long int p)
{
    int res = 1;

    x = x % p;

    while (y > 0)
    {

        if (y & 1)
            res = (res*x) % p;
        y = y>>1;
        x = (x*x) % p;
    }
    return res;
}
int main() {
    long long int a,b;
    cin>>a>>b;
    long long int t;
    cin>>t;
    long long int res;
    res=power(0.5*(a+b),t,mod);
    cout<<res;
  
    return 0;
}