'use strict';

const main = (args) => {
    const input = args.trim().split('\n');
    const K = parseInt(input[0], 10);
    const S = String(input[1]);

    if(S.length > K) {
        let s = S.slice(0, K);
        console.log("%s...", s);
    } else {
        console.log(S);
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf-8'));