process.stdin.resume();
process.stdin.setEncoding('utf8');

function Main(input) {
    var inputs = input.split(" ");
    
    var S = (inputs[0]);
    
    var reverseS = S.split("").reverse().join("");
    var reversedString = ["dreamer", "eraser", "dream", "erase"].map(e => e.split("").reverse().join(""));
    
    var isisis = true;
    for (var i = 0; i < reverseS.length;) {
        var isis = false;
        for (var j = 0; j < reversedString.length; j++) {
            if (reverseS.substr(i, reversedString[j].length) === reversedString[j]) {
                i += reversedString[j].length;
                isis = true;
            }
        }
        if (!isis) {
            isisis = false;
            break;
        }
    }
    console.log(isisis ? "YES" : "NO");
    
}

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