Example

Input

3
y 7
y 6
n 5


Output

1
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

#define each(i,a) for (auto&& i : a)
#define FOR(i,a,b) for (ll i=(a),__last_##i=(b);i<__last_##i;i++)
#define RFOR(i,a,b) for (ll i=(b)-1,__last_##i=(a);i>=__last_##i;i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define __GET_MACRO3(_1, _2, _3, NAME, ...) NAME
#define rep(...) __GET_MACRO3(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define rrep(...) __GET_MACRO3(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
#define pb push_back
#define all(a) (a).begin(),(a).end()
#define chmin(x,v) x = min(x, v)
#define chmax(x,v) x = max(x, v)

const ll linf = 1e18;
const int inf = 1e9;
const double eps = 1e-12;
const double pi = acos(-1);

template<typename T>
istream& operator>>(istream& is, vector<T>& vec) {
    each(x,vec) is >> x;
    return is;
}
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& vec) {
    rep(i,vec.size()) {
        if (i) os << " ";
        os << vec[i];
    }
    return os;
}
template<typename T>
ostream& operator<<(ostream& os, const vector< vector<T> >& vec) {
    rep(i,vec.size()) {
        if (i) os << endl;
        os << vec[i];
    }
    return os;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll n; cin >> n;
    vector<bool> need(n);
    vector<ll> h(n);
    rep(i, n) {
        string s; cin >> s >> h[i];
        need[i] = s == "y";
    }
    priority_queue<P, vector<P>, greater<P>> Q;
    rep(i, n) {
        if (need[i]) {
            Q.push({h[i], i});
        }
    }
    ll ans = 0;
    vector<bool> used(n, false);
    while ( !Q.empty() ) {
        P p = Q.top(); Q.pop();
        ll h0, id; tie(h0, id) = p;
        if (used[id]) continue;
        // cout << id << " :" << endl;
        rep(i, id, n) {
            if (need[i]) {
                used[i] = true;
            }
            else if (h[i] >= h[id]) {
                // cout << i << " " << id << " " << h[i] << " " << h[id] << endl;
                break;
            }
        }
        rrep(i, 0, id) {
            if (need[i]) {
                used[i] = true;
            }
            else if (h[i] >= h[id]) {
                break;
            }
        }
        ++ans;
    }
    cout << ans << endl;
}