x,a,b=list(map(int,input().split()));print((['delicious',['safe','dangerous'][b-a>x]][a-b<0]))
x,a,b=list(map(int,input().split()))

print((('delicious',('safe','dangerous')[b-a>x])[a<b]))
x, a, b = list(map(int, input().split()))
print((["delicious", ["safe", "dangerous"][b - a > x]][a - b < 0]))

x, a, b = list(map(int, input().split()))
print((("delicious", ("safe", "dangerous")[b - a > x])[a < b]))

-print((["delicious", ["safe", "dangerous"][b - a > x]][a - b < 0])) +print((("delicious", ("safe", "dangerous")[b - a > x])[a < b]))