N = input()

i = 0
while i < len(N):
    if i == len(N) - 1:
        if int(N[i]) == 4:
            print(4)
        else:
            print(5)
        exit(0)
    if int(N[i]) < 4:
        i += 1
        break
    if int(N[i]) == 4 and int(N[i+1]) < 4:
        i += 1
        break
    if int(N[i]) == 4 and int(N[i+1]) < 6:
        i += 1
        print(4, end="")
        continue
    if int(N[i]) == 5 and int(N[i+1]) < 4:
        i += 1
        print(4, end="")
        continue
    if int(N[i]) == 5:
        i += 1
        print(5, end="")
        continue
    break

while i < len(N):
    print(5, end="")
    i += 1
print()