#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define int            long long int
#define double         long double
#define F              first
#define S              second
#define pb             push_back
#define si             set <int>
#define vi             vector <int>
#define pii            pair <int, int>
#define vpi            vector <pii>
#define mii            map <int, int>
#define endl           "\n"
#define sz(x)          ((int) x.size())
#define all(p)         p.begin(), p.end()
#define que_max        priority_queue <int>
#define que_min        priority_queue <int, vi, greater<int>>
#define bug(...)       __f (#__VA_ARGS__, __VA_ARGS__)
#define print(a)       for(auto x : a) cout << x << " "; cout << endl
#define print1(a)      for(auto x : a) cout << x.F << " " << x.S << endl
#define print2(a,x,y)  for(int i = x; i < y; i++) cout<< a[i]<< " "; cout << endl

typedef tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update> Set;

template <typename Arg1>
void __f (const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << endl; }
template <typename Arg1, typename... Args>
void __f (const char* names, Arg1&& arg1, Args&&... args)
{
     const char* comma = strchr (names + 1, ',');
     cout.write (names, comma - names) << " : " << arg1 << " | "; __f (comma + 1, args...);
}

const int N = 200005;
int a[N], n, m, k;
string s;

void solve()
{
     cin >> n >> s;
     vector <char> v;

     for (int i = 0; i < n; i++)
     {
          if (sz(v) < 2)
               v.pb(s[i]);
          else
          {
               if (s[i] == 'x')
               {
                    char c = v.back();
                    v.pop_back();
                    if (v.back() == 'f' and c == 'o')
                         v.pop_back();
                    else
                    {
                         v.pb(c);
                         v.pb(s[i]);
                    }
               }
               else
                    v.pb(s[i]);
          }
     }
     cout << sz(v);

}

int32_t main()
{
     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);


     cout << setprecision(9) << fixed;
     clock_t z = clock();
     solve();
     cerr << "Run Time : " << ((double)(clock() - z) / CLOCKS_PER_SEC);

     return 0;
}
/*
  NAME : RISHABH SINGH
  INSTITUTION : DELHI TECHNOLOGICAL UNIVERSITY
*/
#include "bits/stdc++.h"
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define int long long
#define pii pair<int, int>
#define bi __builtin_inf()
#define ll long long
#define mp make_pair
#define ss second
#define pb push_back
#define ff first
#define speed_cubing ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define um unordered_map
#define us unordered_set
#define bp __builtin_popcount
#define ld long double
#define rep(n) for (int i = 0; i < n; i++)
#define pll pair<ll, ll>
#define mx = 1e18;
#define lb(v, val) (lower_bound(v.begin(), v.end(), val) - v.begin())
#define ub(v, val) (upper_bound(v.begin(), v.end(), val) - v.begin())
#define PI 3.1415926535
typedef tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update> pbds;
ll powmod(ll base,ll exp,ll MOD){ll res=1;while(exp>0){if(exp%2==1) res=(res*base)%MOD;base=(base*base)%MOD;exp/=2;}return (res%MOD);}
#define sz(v) (int)v.size()
#define endl '\n'
const int mod = 1e9+7;
ll mul_inv(ll a,ll b = mod) {ll t1=a,t2=b,t3,v1=1,v2=0,v3;while(t2!=1){ll x=t1/t2;t3=t1-x*t2;v3=v1-x*v2;t1=t2,t2=t3;v1=v2,v2=v3;}return(v2+b)%b;}
const int N = 5e5+5;
 
int32_t main(){
   
   speed_cubing
   
   char s,t;
   cin>>s>>t;

   if(s=='Y'){

     cout<<char(t-'a'+'A');

   }
   else 
     cout<<t;
      
   return 0;
}