#include <iostream>
#include <set>
using namespace std;
#define N 100000
class MyHashSet {
private:
set<int> data[N];
public:
MyHashSet() {
}
void add(int key) {
data[key % N].insert(key);
}
void remove(int key) {
data[key % N].erase(key);
}
bool contains(int key) {
return data[key % N].find(key) != data[key % N].end();
}
};
int main() {
return 0;
}