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

long long modulo = pow(10,9) +7;

long long efficientExp(long long base, long long power) {
    if (power == 1) {
        return base % modulo;
    }
    if (power % 2 == 0) { //log 2 speed yay!
        return efficientExp(base*base % modulo, power/2);
    }
    else {
        return efficientExp(base, power-1)*base % modulo;
    }
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    // Input
    long long t;
    long long a;
    long long b;
    cin >> a;
    cin >> b;
    cin >> t;
    // Output + Algorithm - ((a+b)/2)^t % (10^9+7)
    long long growthRate = (a+b)/2; //Should always be an integer.
    long long cells = efficientExp(growthRate, t);
    cout << to_string(cells);
    return 0;
}