#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<iostream>
using namespace std;
int s[1000];
int n,i,j,a,b,ans;
int f[1000];
int main()
{
	freopen("sequenceb.in","r",stdin);
	freopen("sequenceb.out","w",stdout);
	scanf("%d%d%d",&a,&b,&n);
	f[1]=1;
	f[2]=1;
	for (i=3;i<=n;i++){
			f[i]=(a*f[i-1]+b*f[i-2])%7;
		}
	if (n<=100){
		printf("%d",f[n]);
		return 0;
	}
	for (i=1;i<=n;i++)
		s[i]=s[i]*10+s[i+1];
	int t=100;
	for (i=1;i<=n;i++)
		for (j=i+1;j<=n;j++)
		{
			if (s[i]==s[j] && (j-i)<t){
				t=j-i;
			}
		}
	ans=n-n/t*t;
	ans=f[n];
	printf("%d",ans);
}