#include <bits/stdc++.h>
#define MOD 1000000007
typedef long long ll;
typedef unsigned long long ull;
using namespace std;
ll Pow(ll a,ll x)
{
	if (!x) return 1;
	if (x==1) return a;
	ll tmp=Pow(a,x>>1LL);
	tmp=(tmp*tmp)%MOD;
	return (x&1LL)?(tmp*a)%MOD:tmp;
}
int main()
{
	ll a,b,t;
	scanf("%lld%lld%lld",&a,&b,&t);
	ll tmp=(a+b)>>1LL;
	printf("%lld",Pow(tmp,t));
}