"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const K = parseInt(arg[0].split(" ")[0]);
    const S = arg[1].split("");
    
    if(S.length <= K) {
        console.log(S.join(""));
    } else {
        console.log(S.slice(0, K).join("") + "...");   
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));