45. 2675(문자열 반복)

let input = require('fs').readFileSync('/dev/stdin').toString().trim().split('\n');

let T = parseInt(input[0]);
let answer = '';

for(let i = 1; i <= T; i++){
    
    let R = input[i].split(' ');
    let tmp = R[1].split('');
    
    for(let j = 0; j < R[1].length; j++){
        for(let k = 0; k < parseInt(R[0]); k++){
            answer += tmp[j]
        }
    }
    answer += '\n';
}
console.log(answer);