杭電 hdu 1005

#include<iostream>
using namespace std;
#define N 49
int s[N];
int main(){
    int a,b,n;
    while(cin>>a>>b>>n){
        if(a==0&&b==0&&n==0)
            break;
        s[1]=1;
        s[2]=1;
        int i;
        for(i=3;i<=48;++i)
            s[i]=(a*s[i-1]+b*s[i-2])%7;
           
        if(n%49==0)
            cout<<s[1]<<endl;
        else
            cout<<s[n%49]<<endl;
    }
    return 0;
}