#include<stdio.h>
#define mod 1000000007
long long int ipow(long long int base,long long  int exp)
{
    long long int result = 1;
    while (exp)
    {
        if (exp & 1)
            result = (result*base)%mod;
        exp >>= 1;
        base =(base* base)%mod;
    }

    return result;
}

int main()
{
    long long int a,b,t,r1,r2;
    scanf("%lld%lld%lld",&a,&b,&t);
    r1=(a+b)/2;
    r1=ipow(r1,t);
    printf("%lld",r1%mod);
    return 0;
}