//
// 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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