function Main(input) {
	input = input.split("\n");


    const num = Number(input[0]);

    if (input[1].length > num) {
         console.log(input[1].substr( 0, num ) + '...');
    } else {
        console.log(input[1]);
    }
}

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