function Main(input) {
    const s = input.replace("\n", "");
    let ans = "";
    if (s == "B") {
        ans = "C";
    } else if (s == "E") {
        ans = "F";
    } else {
        ans = s + "#";
    }
    console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));