#include <iostream>
#include<stdio.h>
#include<math.h>
#define m 1000000007
using namespace std;
   long long mod(long long a, long long b)
    {
        return(a-(b*(a/b)));
    }
    long long pro(long long c,long long t)
{
    unsigned long long t1,t2;
    if(t==0)
    return(1);
    else
    {
        if(t%2==0)
        return(mod(pro(c,t/2)*pro(c,t/2),m));
        else
        return(mod(mod(c,m)*mod(pro(c,t/2)*pro(c,t/2),m),m));
    }
}
  
int main() {
	 long long a,b,t,amt,i,t1=0,c,d=1;
	scanf("%lld",&a);
	scanf("%lld",&b);
	scanf("%lld",&t);
	c=mod(mod(a,m)+mod(b,m),m)/2;
	d=pro(c,t);
	printf("%lld",d);
	return 0;
}