"use strict";

const main = (input) => {
    const spi = input.split('\n');
    const k = parseInt(spi[0]);
    const s = spi[1];

    const n = s.length;
    if (n <= k) console.log(s);
    else console.log(`${s.substr(0, k)}...`);
};

main(require("fs").readFileSync("/dev/stdin", "utf8"));
