import std.stdio, std.string, std.conv, std.math;

void main() {
	auto ip = readln.split.to!(int[]);
	if(0 < (ip[1] - ip[2])){
		writeln("delicous");
	} else if(ip[0] + 1 > abs(ip[1] - ip[2])){
		writeln("safe");
	} else {
		writeln("dengerous");
	}
}