#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<map>
#include<queue>
#include<map>
#include<vector>
using namespace std;


#define int long long
#define ll long long
#define li int
///____________________原神启动______________________
const int N = 1e5+10;
map<string,int>mp;
void do1(){
   string a;
   cin>>a;
   int b;
   cin>>b;
   mp[a]=b;
   return;

}
void do2(){
   string a;
   cin>>a;
   if(mp.count(a))cout<<mp[a]<<"\n";
   else cout<<"Not found\n";
   return;

}
void do3(){
   string a;
   cin>>a;
    if(mp.count(a))cout<<mp[a]<<"\n";
   else {mp.erase(a);
   cout<<"Deleted successfully";}
   return;
  
}
void do4(){cout<<mp.size()<<"\n";return;
}



void solve(){
 int n;
 cin>>n;
 cout<<n;
 for(int i = 1;i<=n;i++){
   int o;cin>>o;
   if(o==1)do1();
   else if(o==2)do2();
   else if(o==3)do3();
   else do4();
 }

 return;
}





signed main(){
  int t = 1;
  //cin>>t;
  while(t--){
   solve();

  }

   return 0;   


}