#include <iostream>
#include <cstdio>
#define base 1000000007
typedef long long ll;
using namespace std;
ll p(int n,ll m)
{
    if (m==0) return 1LL;
    ll tmp=p(n,m/2);
    tmp=(tmp*tmp)%base;
    if (m%2==1) return (tmp*n)%base;
    return tmp;
}
int main()
{
	int a,b;
    ll t;
	cin>>a>>b>>t;
    ll res=p((b+a)/2,t);
    cout<<res;
}