hdoj1005--Number Sequence

#include<iostream>
using namespace std;

void solve()
{
    int A, B, n;
    while(cin>>A>>B>>n && (A || B || n)) {
        int a[2] = {1, 1};
        for(int i = 0; i < (n %49 - 1) / 2; i++) {
            a[0] = (A * a[1] + B * a[0]) % 7;
            a[1] = (A * a[0] + B * a[1]) % 7;
        }
        if(n % 2) {
            cout<<a[0]<<endl;
        } else {
            cout<<a[1]<<endl;
        }
    }
}

int main()
{
    solve();
    return 0;
}