好像这次周赛（月赛）考的都是数学阿

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
int a,b;
int gcd(int a,int b){ return !b?a:gcd(b,a%b);}
int main()
{
    cin>>a>>b;
    if(gcd(a,b) == 1) printf("YES");
    else printf("NO");
    return 0;
}