import std.stdio;

void main() {
    ulong x, a, b;
    readf(" %s %s %s", &x, &a, &b);

    if (b > x + a) {
        writeln("dangerous");
    } else {
        if (b  > a) {
            writeln("safe");
        } else {
            writeln("delicious");
        }
    }
}