old     = [int(i) for i in input().split(".")]
current = [int(i) for i in input().split(".")]

def verCheck(O, C):
    if O[0] == C[0] and len(O) > 1:
        return verCheck(O[1:len(O)], C[1:len(C)])
    elif O[0] > C[0]:
        return "YES"
    else:
        return "NO"

print(verCheck(old, current))