#include<bits/stdc++.h>
using namespace std;
constexpr int M=1e5+5;
int n,m,T,id[255],pos[M][36];
char s[M],t[M];
int read(){
	int x=0,f=1;char ch=getchar();
	while (!isdigit(ch)) {if (ch=='-') f=-1;ch=getchar();}
	while (isdigit(ch)) x=x*10+ch-48,ch=getchar();
	return x*f;
}
int main(){ T=read();
	iota(id+'a',id+'z'+1,0);
	iota(id+'0',id+'9'+1,26);
	while (T--){
		scanf("%s%s",s+1,t+1);
		n=strlen(s+1);m=strlen(t+1);
		for (int i=0;i<36;i++) 
		for (int i=n;i;i--){
			memcpy(pos[i],pos[i+1],sizeof(pos[i]));
			pos[i][id[s[i]]]=i;
		} int ans=1<<30,l,r;
		for (int i=1;i<=n;i++){
			int x=i-1;
			for (int j=1;j<=m;j++)
				if (!pos[x+1][id[t[j]]])
					{x=-1;break;}
				else x=pos[x+1][id[t[j]]];
			if (!~x) break;
			if (x-i+1<=ans) l=i,r=x;
		}
		for (int i=l;i<=r;i++) putchar(s[i]);
		puts("");
	}
	return 0;
}