const readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});
let inputArr = [];//存放输入的数据
rl.on('line', function(line){
inputArr.push(line);
}).on('close', function(){
console.log(maxString(inputArr[0], inputArr[1]))//调用函数并输出
})
function maxString(a, b) {
if (a.length < b.length) {
[a, b] = [b, a];
}
let res = '';
for(let l = 0; l < b.length; l++) {
for (let r = l + 1; r <= b.length; r++) {
if(r - l > res.length && a.indexOf(b.slice(l, r)) !== -1) {
res = b.slice(l, r);
}
}
}
return res;
}