#include"bits/stdc++.h"
using namespace std;
#define ll long long int
#define mod 1000000007
#define pb push_back

ll mo(ll x,ll n)
{
	if(n==0) return 1;
	ll a=mo(x,n/2);
	if(n%2==0) return (a*a)%mod;
	else return (((a*a)%mod)*x)%mod;
}

int main()
{
	ll a,b,t;
	cin>>a>>b>>t;
	ll c=a+b;
	ll ans=mo(c,t),ans2=mo(2,t),ans3=mo(ans2,mod-2);
	ans=ans*ans3;
	ans%=mod;
	cout<<ans;
}