LongestBlockInString

let input = ['aaabbbccccCCCCC'];
let print = this.print || console.log;
let gets = this.gets || ((arr, index) => () => arr[index++])(input, 0);

let arr = gets().split('');


let tempCount = 1;
let totCount = 1;
let currentSymb = arr[0];
let longest = currentSymb;

for (let i = 0; i <= arr.length; i++) {
    if (arr[i] === arr[i - 1]) {
        tempCount++;
        currentSymb += arr[i];
    } else {
        if (tempCount > totCount) {
            totCount = tempCount;
            longest = currentSymb
        } tempCount = 1;
        currentSymb = arr[i];
    }
}
console.log(longest)