#include<bits/stdc++.h>
using namespace std;
#define min(a,b)(a<b?a:b)
#define max(a,b)(a>b?a:b)
#define int long long
inline int read()
{
    char ch=getchar();
    int s=0,w=1;
    while(ch<'0'||ch>'9')
    {
        if(ch=='-'){w=-1;}
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        s=(s<<1)+(s<<3)+ch-48;
        ch=getchar();
    }
    return w*s;
}
inline void out(int x)
{
    if(x<0){putchar('-'),x=-x;}
    if(x>9){out(x/10);}
    putchar(x%10+'0');
}
inline void print(int x)
{
    out(x);
    putchar('\n');
}
inline string read_char()
{
    char ch=getchar();
    string st1="";
    while(!((ch>='a')&&(ch<='z'))){ch=getchar();}
    while((ch>='a')&&(ch<='z')){st1+=ch,ch=getchar();}
    return st1;
}
map<string,int>mp;
signed main()
{
    mp.clear();
    int q=read();
    while(q--)
    {
        int op=read();
        if(op==1)
        {
            string name=read_char();
            int score=read();
            mp.insert(pair<string,int>(name,score));
            printf("OK\n");
        }
        else
        {
            if(op==2)
            {
                string name=read_char();
                if(!mp.count(name)){printf("Not found\n");}
                else{print(mp[name]);}
            }
            else
            {
                if(op==3)
                {
                    string name=read_char();
                    if(!mp.count(name)){printf("Not found\n");}
                    else{mp.erase(name);printf("Deleted successfully\n");}
                }
                else{print(mp.size());}
            }
        }
    }
	return 0;
}

不知道哪错了