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

const int N=1e6+10;
int t;
map<string,long long> mp;
void solve()
{
	int n=0;
	cin>>n;
	while(n--)
	{
		int op=0;
		string s;
		cin>>op;
		if(op==1)
		{
			long long score=0;
			cin>>s>>score;
                        //mp.insert(map<string,long long>::value_type(s,score));
			mp[s]=score;
			cout<<"OK"<<endl;
		}
		else if(op==2)
		{
			cin>>s;
			if(mp.find(s)!=mp.end()) {
				cout<<mp.at(s)<<endl;
			}else cout<<"Not found"<<endl;
		}
		else if(op==3)
		{
			cin>>s;
			if(mp.find(s)!=mp.end()) {
			     mp.erase(s);
				cout<<"Deleted successfully"<<endl;
			}else cout<<"Not found"<<endl;
		}
		else if(op==4)
		{
			cout<<mp.size()<<endl;
		}
	}
	return;
}
int main()
{
	solve();
	return 0;
}

注释的交上全wa ,直接赋值就对了，为啥