S = input()
N = len(S)

if S < "4"*N:
    exit(print("5"*(N-1)))

ans = [-1]*N
small = False
idx = -1
for i in range(N):
    if not small:
        if 4 == int(S[i]):
            ans[i] = 4
        elif 5 == int(S[i]):
            ans[i] = 5
        elif 5 < int(S[i]):
            ans[i] = 5
            small = True
        else:
            ans[i] = 5
            idx = i
            small = True
    else:
        ans[i] = 5

if idx != -1:
    for i in reversed(range(idx)):
        if S[i] == "5":
            ans[i] = 4
            break

print("".join(map(str, ans)))