#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

long int modularPow(long base, long exponent, long modulus);

int main() {

    int a, b;
    long int t;
    scanf("%i %i %li", &a, &b, &t);
    printf("%li", modularPow((a+b)/2, t, 1000000007));
    
    return 0;
        
}

long int modularPow(long base, long exponent, long mod){
    int result = 1;
    while (exponent > 0){
        if (exponent % 2 == 1)
           result = (result * base) % mod;
        exponent /= 2;
        base = (base * base) % mod;
    }
    return result;
}