第一个测试点RE，求助

#include<bits/stdc++.h>
using namespace std;
int n;
int liex;
int liey;
int tux;
int tuy;
int gcd(int a,int b)
{
	int c=0;
	while(a%b!=0)
	{
		c=a%b;
		a=b;
		b=c;
	}
	return b;
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>liex>>liey;
		cin>>tux>>tuy;
		if(gcd(abs(liex-tux),abs(liey-tuy))!=1) cout<<"yes"<<endl;
		else cout<<"no"<<endl;
	}
}