import std.stdio;
import std.string;
import std.range;
import std.conv;

void main()
{
	auto ip = readln.split.to!(int[]), X = ip[0], A = ip[1], B = ip[2];
	if(A >= B) {
		writeln("delicious");
	} else {
		if(B-A > X) {
			writeln("dangerous");
		} else {
			writeln("safe");
		}
	}
}
