HDU(1525)Euclid's Game

#include <iostream>#include <stdio.h>#include <string.h>#include <algorithm>#include <set>using namespace std;int main() {    int a,b;    while(scanf("%d%d",&a,&b)&&(a+b)){        if(a<b) swap(a, b);        int flag = 1;        while(1){            if(a == b || a >= 2*b)                break;            else{                a = a - b;                swap(a,b);                flag = !flag;            }        }        if(flag)            printf("Stan wins\n");        else            printf("Ollie wins\n");    }    return 0;}