#include <bits/stdc++.h>
#define REP(k,n) for(int (k)=0;(k)<(n);(k)++)
using ll = long long;
using ull = unsigned long long;
using namespace std;

string s;
int a=0;

void solve()
{
    cin>>s;
    REP(i,s.length()) if(s[i]=='i') a++;
    cout << a << endl;
}

int main(){cin.tie(0);ios_base::sync_with_stdio(false);solve();return 0;}