socant (12)

#include <bits/stdc++.h>
using namespace std;
#define IMPOSSIBLE puts("NU"); exit(0);
using ll = long long;
constexpr ll ROOT = 2021, BASE = 10;

void shock(ll &n) {
    if (n < ROOT) {
        IMPOSSIBLE
    }

    ll p = 1;
    while (ROOT * p <= n) {
        p *= BASE;
    }
    n -= (ROOT * p / BASE);
}

signed main() {
    ll n;
    cin >> n;

    ll r = 0;
    do {
        r++;
        shock(n);
    } while(n);
    cout << r << endl;
    return 0;
}