WAWAWAWA

#include<bits/stdc++.h>
using namespace std;
int n,sum,c[100002];
string name[100002];
long long s[100002];
map<string,long long>a;
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>c[i];
		if(c[i]!=4) cin>>name[i];
		if(c[i]==1) cin>>s[i];
	}
	for(int i=1;i<=n;i++){
		if(c[i]==1){
			if(!a[name[i]]) sum++;
			a[name[i]]=s[i];
			cout<<"OK\n";
		}
		else if(c[i]==2){
			if(!a[name[i]]) cout<<"Not found\n";
			else cout<<a[name[i]]<<"\n";
		}
		else if(c[i]==3){
			if(!a[name[i]]) cout<<"Not found\n";
			else{
				a[name[i]]=0;sum--;
				cout<<"Deleted successfully\n";
			}
		}
		else if(c[i]==4){
			cout<<sum;
		}
	}
	return 0;
}