function Main(input) {
    var N = parseInt(input[0], 10);
    var S = input[1];
    var sList = S.split('');
    
    var alp = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    var list = alp.split('');

    var result = [];

    for (var i = 0; i < S.length; i++) {
        var index = list.indexOf(sList[i]) + N;
        if (index > 25) {
            index = index - 26;
        }
        result.push(list[index]);
    }

    console.log(result.join(''));
}

Main(require("fs").readFileSync("/dev/stdin", "utf8").trim().split(/\n|\s/));