#include<bits/stdc++.h>
using namespace std;
int T,n,m;string s,t;
void solve1(){
	for(int i=0;i<n;i++)
		if(s[i]==t[0]){
			cout<<"-1\n";
			return;
		}
	cout<<"0\n";
	return;
}void solve2(){
	int ans=0;
	for(int i=1;i<n;i++)
		if(s[i]==t[1]&&s[i]!=s[i-1])
			ans++;
	cout<<ans<<"\n";
	return;
}void solve3(){
	int c=0,d=0;
	for(int i=0;i<n;i++)
		if(s[i]==t[0])c++;
		else d++;
	if(n%2==1&&c>d+1){
		cout<<"-1\n";
		return;
	}if(n%2==0&&c>d){
		cout<<"-1\n";
		return;
	}c=0;
	for(int i=1;i<n;i++)
		if(s[i]==s[i-1]&&s[i]==t[0])c++;
	cout<<c<<"\n";
	return;
}void solve4(){
	int ans=0;
	for(int i=0;i<n-2;i++)
		if(s[i]==t[0]&&s[i+1]==t[1]&&s[i+2]==t[2])
			ans++;
	cout<<ans<<"\n";
	return;
}void solve5(){
	int ans=0;
	for(int i=0;i<n-2;i++)
		if(s[i]==t[0]&&s[i+1]==t[1]&&s[i+2]==t[2])
			ans++;
	cout<<(ans+1)/2<<"\n";
	return;
}int g[200010],tot,h[200010],to;
void solve6(){
	int c=0,d=0;tot=to=0;
	for(int i=0;i<n;i++)
		if(s[i]==t[0])c++;
		else{
			d++;
			g[++tot]=i;
		}
	int maxc=(d+1)*2;
	if(c>maxc){
		cout<<"-1\n";
		return;
	}int ans=0;
	if(tot){
		h[++to]=g[1];
		for(int i=1;i<tot;i++)
			h[++to]=g[i+1]-g[i]-1;
		h[++to]=n-g[tot]-1;
		sort(h+1,h+to+1);
		assert(to==d+1);
		int st=1,ed=to;
		while(h[ed]>=3&&st<=ed){
			ans++;
			int c=min(2-h[st],h[ed]-2);
			h[ed]=h[ed]+h[st]-c;h[st]=c;
			if(h[st]>=2)st++;
			if(h[ed]<3)ed--;
		}
	}cout<<ans<<"\n";
	return;	
}signed main(){
	freopen("shin.in","r",stdin);
	freopen("shin.out","w",stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);cin>>T;
	while(T--){
		cin>>s>>t;
		n=(int)s.length();
		m=(int)t.length();
		if(m==1)solve1();
		else if(m==2&&t[0]!=t[1])
			solve2();
		else if(m==2&&t[0]==t[1])
			solve3();
		else if(m==3&&t[0]!=t[2]){
			if(t[1]==t[2]){
				reverse(t.begin(),t.end());
				reverse(s.begin(),s.end());
			}solve4();
		}else if(m==3&&t[0]!=t[1])
			solve5();
		else solve6();
	}return 0;
}