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

unsigned long mypow(unsigned long x, unsigned long exp)
{
    int temp;
    if( exp == 0)
        return 1;
    temp = mypow(x, exp/2);
    if (exp%2 == 0)
        return temp*temp;
    else
        return x*temp*temp;
}

int main() {

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    unsigned long a,b,t;
    scanf("%ld",&a);
    scanf("%ld",&b);
    scanf("%ld",&t);
    
    printf ("%ld",mypow(0.5*(a+b), t)%(1000000007));
    return 0;
}