#include <iostream>
using namespace std;

struct Node {
    int type;
    Node *prev;
};
struct Stack {
    int size = 0;
    Node *top = nullptr;
};
void pushNode(Stack *stPtr, int newType);
void extractNode(Stack *stPtr);
void clear(Stack *stPtr);
int commonSize = 0, maximum = 0;
int main() {
    int requestNumber, stackAmount, maxAmount;
    cin >> requestNumber >> stackAmount >> maxAmount;
    Stack **array = new Stack *[stackAmount];
    for (int i = 0; i < stackAmount; ++i) {
        array[i] = new Stack;
    }
    bool status = true;
    for (int i = 0; i < requestNumber && status; ++i) {
        char command;
        int newType, stackIndex;
        cin >> command >> stackIndex >> newType;
        if (command == '+') {
            pushNode(array[stackIndex - 1], newType);
        }
        else if (command == '-') {
            if (array[stackIndex - 1]->size == 0 || array[stackIndex - 1]->top->type != newType) {
                status = false;
            }
            else {
                extractNode(array[stackIndex - 1]);
            }
        }
    }
    if (status && commonSize == 0) {
        cout << maximum << endl;
    }
    else {
        cout << "Error" << endl;
    }
    for (int i = 0; i < stackAmount; ++i) {
        clear(array[i]);
    }
    delete []array;
    return 0;
}
void pushNode(Stack *stPtr, int newType) {
    Node *newNode = new Node {newType, stPtr->top};
    stPtr->top = newNode;
    ++stPtr->size;
    ++commonSize;
    maximum = (maximum < commonSize) ? commonSize : maximum;
}
void extractNode(Stack *stPtr) {
    Node *oldTop = stPtr->top;
    stPtr->top = oldTop->prev;
    delete oldTop;
    --stPtr->size;
    --commonSize;
}
void clear(Stack *stPtr) {
    while(stPtr->size != 0) {
        extractNode(stPtr);
    }
}