//
//  main.cpp
//  F - Misha and Changing Handles
//
//  Created by Farrah Tharwat on 03/02/2023.
//
 
#include <iostream>
#include <map>
#define endl '\n'
using namespace std;
string getSource(string s, int index, string old[],string neww[]){
    for(int i=index-1; i>=0; i--)
    {
        if(neww[i] == s)
            s = old[i];
    }
    return s;
}
int main() {
    int t;
    cin>>t;
    int oc=0;
    string o,n;
    string old[t],neww[t];
    map <string,string> ans;
    for(int i=0;i<t;i++){
        cin>>old[i]>>neww[i];
        string src = getSource(old[i], i,old,neww);
        ans[src]=neww[i];
    }
    cout<<ans.size()<<endl;
 
}
 

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5
Misha ILoveCodeforces
Vasya Petrov
Petrov VasyaPetrov123
ILoveCodeforces MikeMirzayanov
Petya Ivanov