E

#include <array>
#include <iostream>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <stack>

using namespace std;

#define int long long

const long long INF = 1e18 + 7;
const int MAXN = 2e5 + 10;
const int N = 1e5 + 10;

int n, k, p;
//array<stack<int>, N> a;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin >> n >> k >> p;
    int cnt = 0, maxi = 0;
    vector<stack<int>> a(k);
    for (int i = 0; i < n; ++i) {
        char type;
        int pos, x;
        cin >> type >> pos >> x;
        --pos;
        if (type == '+') {
            a[pos].push(x);
            ++cnt;
            maxi = max(maxi, cnt);
            if (cnt > p) {
                cout << "Error";
                return 0;
            }
        } else {
            if (a[pos].empty() || a[pos].top() != x) {
                cout << "Error";
                return 0;
            }
            a[pos].pop();
            --cnt;
        }
    }
    if (cnt) {
        cout << "Error";
        return 0;
    } else {
        cout << maxi << '\n';
    }
}