void solve(){
}
void main(){
	int x, a, b;
	readf("%d %d %d", &x, &a, &b);
	if(b<=a)writeln("delicious");
	else if(b<=a+x)writeln("safe");
	else writeln("dangerous");
}
     
import std.stdio, std.conv, std.algorithm, std.numeric, std.string, std.math, std.range;
const long mod = 10^^9+7;
alias instr = () => readln().chomp();
T inelm(T= int)(){ return to!(T)( readln().chomp() ); }
T[] inary(T = int)(){ return readln().chomp().split().to!(T[])(); }

