#include<bits/stdc++.h>
using namespace std;
int n,opt,num,ans;
string name;
map<string,int> ds;
int main(){
	cin>>n;
	while(n--){
		cin>>opt;
		if(opt==1){
			cin>>name>>num;
			ds[name]=num;
			cout<<"OK"<<endl;
		}else if(opt==2){
			cin>>name;
			if(ds.find(name)!=ds.end())
				cout<<ds[name]<<endl;
			else cout<<"Not found"<<endl;
		}else if(opt==3){
			cin>>name;
			if(ds.find(name)!=ds.end()){
				ds.erase(ds.find(name));
				cout<<"Deleted successfully"<<endl;
			}else
				cout<<"Not found"<<endl;
		}else
			cout<<ans<<endl;
	}
	return 0;
}