#include <iostream>
#include <cstdio>
#include <iomanip>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <utility>
#include <numeric>
#include <algorithm>
#include <functional>
#include <cctype>
#include <complex>
#include <string>
#include <sstream>
#include <fstream>
#include <cassert>
using namespace std;

//common

typedef int  i32;
typedef long long i64,ll;
typedef long double ld;

#define BR "\n"
#define ALL(c) (c).begin(),(c).end()
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define FOR(i,l,r) for(int i=(int)l;i<(int)(r);++i)
#define EACH(it,o) for(auto it = (o).begin(); it != (o).end(); ++it)
#define IN(l,v,r) ((l)<=(v) && (v)<(r))

//config
//#define NDEBUG
//#define INF 1<<30
//#define EPS 1e-8
//const ll MOD =100000007;

//debug
#ifdef NDEBUG
#define DUMP(x)
#define DUMPLN(x)
#define DEBUG(x)
#define DEBUGLN(x)
#define LINE()
#define LINELN()
#define CHECK(exp,act)
#define STOP(e)
#else
#define DUMP(x)  cerr << #x << " = " << (x)
#define DUMPLN(x)  DUMP(x) <<endl
#define DEBUG(x) DUMP(x) << LINE() << " " << __FILE__
#define DEBUGLN(x) DEBUG(x)<<endl
#define LINE()    cerr<< " (L" << __LINE__ << ")"
#define LINELN()    LINE()<<endl
#define CHECK(exp,act)  if(exp!=act){DUMPLN(exp);DEBUGLN(act);}
#define STOP(e)  CHECK(e,true);if(!(e)) exit(1);
#endif

template<class T> inline string toString(const vector<T>& x) {
	stringstream ss;
	REP(i,x.size()){
		if(i!=0)ss<<" ";
		ss<< x[i];
	}
	return ss.str();
}

template<class T> inline string toString(const vector<vector<T> >& map) {
	stringstream ss;
	REP(i,map.size()){
		if(i!=0)ss<<BR;
		ss<< toString(map[i]);
	}
	return ss.str();
}
template<class K,class V>  string toString(map<K,V>& x) {
	string res;stringstream ss;
	for(auto& p:x)ss<< p.first<<":" << p.second<<" ";
	return ss.str();
}

string BITtoString(int bit){
    stringstream ss;
    while(bit!=0){ss<<(bit%2);bit/=2;}
    string res=ss.str();reverse(ALL(res));
    return res;
}

template<typename T> inline T pmod(T v,T MOD){
	return (v%MOD+MOD)%MOD;
}
#define nextInt(n) scanf("%d",&n)
#define defInt(n) int n;nextInt(n)
#define nextLong(n) scanf("%lld",&n)
#define defLong(n) ll n;nextLong(n)
#define nextDouble(n) scanf("%lf",&n)



namespace ShortestPath{
    const int INF=1<<30;
    struct Edge{
        int from,to,cost;
        Edge(int from,int to,int cost)
            : from(from),to(to),cost(cost) {};
    };
    ostream& operator <<(ostream& os,const Edge& e){
            os<<"("<<e.from<<"->"<<e.to<<")";
            return os;
    }
    struct Task{
        int prev,pos,cost;
        Task(int prev,int pos,int cost)
            :prev(prev),pos(pos),cost(cost){};
        bool operator>(const Task& r) const{
            return cost>r.cost;
        }
    };
    typedef vector<vector<Edge> > Graph;
    typedef  vector<vector<int> > Mat;

    // 最大も可
    // 負の閉路が判定可能
    //O(V*E)
    vector<int> bellmanFord(Graph g,int s,vector<int> prev){
        const int V=g.size();
        vector<int> d(V,INF);d[s]=0;
        fill(ALL(prev),-2);
        REP(k,V){
            REP(i,V)REP(j,g[i].size()){
                Edge e=g[i][j];
                if(d[e.to]>d[e.from]+e.cost){
                    d[e.to]=d[e.from]+e.cost;
                    prev[e.to]=e.from;
                    if(k==V-1)d[e.to]=-INF;
                }
            }
        }
        return d;
    }    

    //verified by codoforces 144D http://codeforces.com/contest/144/submission/4976825
    // // 負の辺がない
    // // O(E*logV)
    vector<int> dijkstra(const Graph& g,const int s,vector<int>& prev){
        const int V=g.size();
        vector<int> d(V,INF);d[s]=0;
        fill(ALL(prev), -2);
        priority_queue<Task,vector<Task>,greater<Task> > que;
        que.push(Task(-1,s,0));
        while(!que.empty()){
            Task task=que.top();que.pop();
            //if(prev[task.pos]!=-2)continue;
            if(d[task.pos]<task.cost)continue;
            prev[task.pos]=task.prev;
            EACH(e,g[task.pos]){
                if(d[e->to]>d[e->from]+e->cost){
                    d[e->to]=d[e->from]+e->cost;
                    que.push(Task(e->from,e->to,d[e->to]));
                }
            }   
        }
        return d;
    }
    vector<int> dijkstra(const Graph& g,const int s){
        vector<int> prev(g.size());return dijkstra(g,s,prev);
    }

}
using namespace ShortestPath;


class Main{
public:

    int N;
    vector<string> ss;
    map<string,int> lmap;
    map<int,string> ilmap;
    map<string,int> gmap;
    map<int,string> igmap;
    bool input(){
        //   ifstream cin("in");
        //  ofstream cout( "out" );
        cin >> N;
        REP(i,N){
            string s;cin >> s;
            if(s=="goto")cin >> s;
            
            if(s[s.size()-1]==':'){
                lmap[s.substr(0,s.size()-1)]=i;
                ilmap[i]=s.substr(0,s.size()-1);
            }else{
                gmap[s.substr(0,s.size()-1)]=i;
                igmap[i]=s.substr(0,s.size()-1);
            }
        }
        return true;
    }

    void run(){
        input();

        Graph g(N+1);

        REP(i,N){
            if(igmap.count(i)){
                g[i].push_back(Edge(i,i+1,1));
                g[i].push_back(Edge(i,lmap[igmap[i]],0));
            }else{
                g[i].push_back(Edge(i,i+1,0));
            }
        }
        cout <<dijkstra(g,0)[N]<<endl;
    }
};

int main(){
	//cout <<fixed<<setprecision(3);	
	//ios::sync_with_stdio(false);
	Main().run();
	return 0;
}

Measured memory_bytes: 1264