// Slower C++ solution:


#include <bits/stdc++.h>

#include <ext/rope>

#define VALHALLA cin.tie(0);ios_base::sync_with_stdio(false);cout<<fixed<<setprecision(13);

#define endl "\n"

#define pb push_back

#define all(v) v.begin(),v.end()

#define debug(x) std::cerr << #x << ": " << (x) << '\n';

#define sz(x) (int)x.size()

#define fast(map_name) map_name.reserve(1024);map_name.max_load_factor(0.25);

using namespace std;

using namespace __gnu_cxx;

typedef long long int ll;

typedef pair<int,int> ii;

typedef complex<double> point;

const double epsilon=1e-9;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int mod=1e9+7;

/* VARIABLE DECLARATION START */

int arr[int(1e5+1)];

int dp[int(1e5+1)][5];

string s;

/*  FUCNTION TEMPLATE STARTS  HERE */



double dot(point a,point b){ return (conj(a)*b).real() ; }

double cross(point a,point b){ return (conj(a)*b).imag() ; }

double dist(point a, point b){ return abs(a-b); }

struct neal {

static uint64_t splitmix64(uint64_t x)

 {

    x += 0x9e3779b97f4a7c15;

    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;

    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;

    return x ^ (x >> 31);

}

size_t operator()(uint64_t x) const

 {

    static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

    return splitmix64(x + FIXED_RANDOM);

}

};

struct HASH{

  size_t operator()(const pair<int,int>&x)const{

    return (size_t) x.first * 37U + (size_t) x.second;

  }

};

bool isprime(ll n) {

    if (n == 2 || n == 3) return true;

    if (n < 2 || n % 2 == 0 || n % 3 == 0) return false;

    for (ll i = 6; (i - 1) * (i - 1) <= n; i += 6) {

        if (n % (i - 1) == 0 || n % (i + 1) == 0) {

            return false;

        }

    }

    return true;

}

inline ll exp(ll a, ll b, ll mod) {

    ll n = 1;

    ll p = a;

    while (b > 0) {

        if (b % 2 == 1) {

            n *= p;

            n %= mod;

        }

        p *= p;

        p %= mod;

        b /= 2;

    }

    return n;

}



inline bool comp(double a,double b)

{

  return (fabs(a-b)<epsilon);

}

ll gcd(ll u, ll v) {

  ll r;

  while (0 != v) {

    r = u % v; u = v; v = r;

  }

  return u;

}

int solve(int index,int rock,int paper,int dec)

{

  if(index<0)

    return 0;

  if(dp[index][dec]!=-1)return dp[index][dec];

  int ans=0;

  if(rock>=paper+1)

  {

    if(s[index]=='p')

    {

      int val1=solve(index-1,rock,paper+1,1);

      int val2=-1+solve(index-1,rock+1,paper,0);

      if(val1>val2)

        return dp[index][1]=val1;

      else

        return dp[index][0]=val2;

    }

    else

    {

      int val1=1+solve(index-1,rock,paper+1,1);

      int val2=solve(index-1,rock+1,paper,0);

      if(val1>val2)

        return dp[index][1]=val1;

      else

        return dp[index][0]=val2;

    }

  }

  else

  {

    if(s[index]=='p')

    ans=-1+solve(index-1,rock+1,paper,0);

    else

    ans=solve(index-1,rock+1,paper,0);

    return dp[index][0]=ans;

  }

}





/*  FUCNTION TEMPLATE ENDS HERE */

int main()

{

   VALHALLA

  cin>>s;

  memset(dp,-1,sizeof(dp));

  cout<<max(solve(sz(s)-1,0,0,0),solve(sz(s)-1,0,0,1))<<endl;





}


// Faster C++ solution for the same problem (measured speedup: 2.9522345932678364x):


#include <bits/stdc++.h>

#include <ext/rope>

#define VALHALLA cin.tie(0);ios_base::sync_with_stdio(false);cout<<fixed<<setprecision(13);

#define endl "\n"

#define pb push_back

#define all(v) v.begin(),v.end()

#define debug(x) std::cerr << #x << ": " << (x) << '\n';

#define sz(x) (int)x.size()

#define fast(map_name) map_name.reserve(1024);map_name.max_load_factor(0.25);

using namespace std;

using namespace __gnu_cxx;

typedef long long int ll;

typedef pair<int,int> ii;

typedef complex<double> point;

const double epsilon=1e-9;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int mod=1e9+7;

/* VARIABLE DECLARATION START */

/*  FUCNTION TEMPLATE STARTS  HERE */



double dot(point a,point b){ return (conj(a)*b).real() ; }

double cross(point a,point b){ return (conj(a)*b).imag() ; }

double dist(point a, point b){ return abs(a-b); }

struct neal {

static uint64_t splitmix64(uint64_t x)

 {

    x += 0x9e3779b97f4a7c15;

    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;

    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;

    return x ^ (x >> 31);

}

size_t operator()(uint64_t x) const

 {

    static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

    return splitmix64(x + FIXED_RANDOM);

}

};

struct HASH{

  size_t operator()(const pair<int,int>&x)const{

    return (size_t) x.first * 37U + (size_t) x.second;

  }

};

bool isprime(ll n) {

    if (n == 2 || n == 3) return true;

    if (n < 2 || n % 2 == 0 || n % 3 == 0) return false;

    for (ll i = 6; (i - 1) * (i - 1) <= n; i += 6) {

        if (n % (i - 1) == 0 || n % (i + 1) == 0) {

            return false;

        }

    }

    return true;

}

inline ll exp(ll a, ll b, ll mod) {

    ll n = 1;

    ll p = a;

    while (b > 0) {

        if (b % 2 == 1) {

            n *= p;

            n %= mod;

        }

        p *= p;

        p %= mod;

        b /= 2;

    }

    return n;

}



inline bool comp(double a,double b)

{

  return (fabs(a-b)<epsilon);

}

ll gcd(ll u, ll v) {

  ll r;

  while (0 != v) {

    r = u % v; u = v; v = r;

  }

  return u;

}





/*  FUCNTION TEMPLATE ENDS HERE */

int main()

{

   VALHALLA

   string s;

   cin>>s;

   int n=sz(s);

   int rock=n;

   int paper=0;

   int score=0;

   for(auto x:s)if(x=='p')score++;

    int ans=INT_MAX;

   while(paper<=rock)

   {

     ans=min(ans,score);

     paper++;

     rock--;

     score--;

   }

   cout<<-ans<<endl;





}