#include<iostream>
#include<cstdio>
#define int long long
using namespace std;
int n,m,len,a,b,vis[1000001],t,ans;
void find(int x){
	for(int i=1;i*i<=x;i++){
		if(x%i==0){
			vis[++len]=i;
			if(i*i!=x)vis[++len]=x/i;
		}
	}
}
bool check(int x){
	if((b-a)/x+1>n)return false;
	if((a-1)/x+(b-a)/x+1+(m-b)/x>=n)return true;
	return false;
}
signed main(){
	scanf("%lld",&t);
	for(int i=1;i<=t;i++){
		scanf("%lld%lld%lld%lld",&n,&m,&a,&b);
		if(a>b)swap(a,b);
		ans=len=0;
		find(b-a);
		for(int j=1;j<=len;j++)if(check(vis[j]))ans++;
		printf("%lld\n",ans);
	}
}
/*
n=4,m=16,a=2,b=8;
***~~~a~~~~~~~~~~~b~~~~~~~~~~~~~~~m
*** - 2 - - - - - 8 - - - - - - - 16
***|-|-----------|-|---------------|
*** |        |    |           |
*** |        |    |           |
***\|/       |   \|/          |
***(a-1)/x  \|/   1          \|/
***      (b-a)/x          (m-b)/x
*/