function Main(input) {
    var line = input.split("\n");
    var A = line[0];
    var B = line[1];
    var res = "";
    var indexSum = 0;
    var elemSum = 0;
    var pair = 0;


    if (A.length != B.length) {
        res = "NO"
    }
    for (var i = 0; i < A.length; i = i + 1) {
        pair = B.indexOf(A[i]);
        indexSum += pair
        elemSum += i;
        B[pair] = null;
    }
    res = (indexSum == elemSum) ? "YES" : "NO";
    
    console.log(res);
}

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