function solution(s) {
var answer = '';
let arr = s.split(' ');
for(let i = 0; i < arr.length; i++){
for(let j = 0; j < arr[i].length; j++){
j % 2 == 0 ?
answer += arr[i][j].toUpperCase() :
answer += arr[i][j].toLowerCase()
}
answer += ' ';
}
answer = answer.slice(0, -1);
return answer;
}
성공