#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

const unsigned long long int peak = (int) 1e9+7;
static unsigned long long int base;
unsigned long long int res(unsigned long long int t){
	//cout << "res:" << t << "\n";
    if(t==1){
        return base;
    }
    if(t==0){
        return 1;
    }
    unsigned long long int half = t/2;
    unsigned long long int ele = res(half);
    if(t%2==0){
        return (unsigned long long int) (ele*ele)%peak;
    }
    else{
        return (unsigned long long int) ((ele*ele)%peak)*base%peak;
    }
}
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    unsigned long long int a,b;
    unsigned long long int t;
    cin>>a>>b>>t;
    base = (a+b)/2;
    // cout << peak <<"\n";
    // cout << base <<"\n";
    cout << res(t) <<"\n";
    return 0;
}