money

#include<iostream>
#include<string>
#include<list>
#include<algorithm>
#include <iomanip>
using namespace std;
int main(){
    int a;
    cin>>a;
    int b;
    string c[a];
    int s[a];
    int x;
    float t;
    string w;
    int k=0;
    int j=0;
    for(int i=0;i<a;i++){
        c[i] = "0";
        s[i] = 0;
    }
    for(int i=0;i<a;i++){
        cin>>b;
        if(b == 1){
            int r = 0;
            cin>>w>>x;
            for(int j=0;j<a;j++){
                if(w == c[j] && r != 1){
                        r = 1;
                    s[j] = s[j] + x;
                    //cout<<s[j]<<endl;
                }
                else if(c[j] == "0" && r != 1){
                    r = 1;
                    s[j] = x;
                    c[j] = w;
                    //cout<<s[j]<<endl;
                }
            }
        }
        else if(b == 2){
            cin>>w;
            for(int j=0;j<a;j++){
                if(w == c[j]){
                    s[j] = 0;
                    //cout<<s[j]<<endl;
                }
            }
        }
            else{
                    int o=0;
                cin>>w;
                for(int j=0;j<a;j++){
                    if(w == c[j] && o != 1){
                        o=1;
                        cout<<s[j]<<endl;
                    }
                }
                if(o == 0){
                    cout<<0<<endl;
                }
            }
    }
    t = 0;
    for(int i=0;i<a;i++){
        if(s[i] != 0){
            t = t + s[i];
            k++;
        }
    }
    t = t / k;
    cout<<setprecision(2)<<fixed<<t;
    return 0;
}