a,b,c,d=map(int,input().split())
if (a ==b and b==c and c==d):
    print("Fish At Constant Depth")
elif (a <b and b<c and c<d):
    print("Fish Rising")    
elif (a >b and b>c and c>d):
    print("Fish Diving")    
else:
    print("No Fish")