"use strict";
function main(input) {
    const line = input.split("\n");
    let a = parseInt(line[0]);
    let str = line[1];
    let str1 = [];
    var l = str.length;
    if(l<=a) console.log(str);
    else{
        for(let i=0; i<a; ++i) str1[i] = str[i];
        console.log(str1.join('')+"...");
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));