#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define rep3(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep2(i, a, b) rep3(i, a, b, 1)
#define rep1(i, n) rep2(i, 0, n)
#define rep0(n) rep1(aaaaa, n)
#define ov4(a, b, c, d, name, ...) name
#define rep(...) ov4(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define per(i, a, b) for (ll i = (a) - 1; i >= (b); i--)
#define fore(e, v) for (auto &&e : v)
#define all(a) begin(a), end(a)
#define sz(a) (ssize(a))
#define lb(v, x) (lower_bound(all(v), x) - begin(v))
#define eb emplace_back

template <typename T, typename S> bool chmin(T &a, const S &b) {
  return a > b ? a = b, 1 : 0;
}
template <typename T, typename S> bool chmax(T &a, const S &b) {
  return a < b ? a = b, 1 : 0;
}
const int INF = 1e9 + 100;
const ll INFL = 3e18 + 100;
#define i128 __int128_t
struct _ {
  _() { cin.tie(0)->sync_with_stdio(0), cout.tie(0); }
} __;

int main() {
  string S;
  cin >> S;
  int N = sz(S);
  string pre;
  rep(i, N) {
    if (S[i] == '5' || S[i] == '4')
      pre += S[i];
    else
      break;
  }
  if (sz(pre) == N) {
    cout << pre << '\n';
    return 0;
  }
  if (S[sz(pre)] > '5') {
    cout << pre << string(N - sz(pre), '5') << '\n';
    return 0;
  }
  int f = 0;
  per(i, sz(pre), 0) {
    if (pre[i] == '5') {
      pre[i] = '4', f = 1;
      break;
    }
  }
  if (!f) {
    cout << string(N - 1, '5') << '\n';
  } else {
    cout << pre << string(N - sz(pre), '5') << '\n';
  }
}