codeforce393A

#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    string a,b;
    int n,i,e,t,flag;
    while(cin>>a)
    {
        n=i=e=t=flag=0;
        for(int j=0; j<=a.length(); j++)
        {
            if(a[j]=='n')
                n++;
            else if(a[j]=='t')
                t++;
            else if(a[j]=='e')
                e++;
            else if(a[j]=='i')
                i++;
        }
        int min=i;
        if(i==0||t==0||e/3==0||n/3==0)
        {
            cout<<0<<endl;
            break;
        }
        if(t<min)
            min=t;
        if(e/3<min)
            min=e/3;
        if(n/3<min)
            flag=1;
        if(flag==1)
                cout<<(n-3)/2+1<<endl;
        else
            cout<<min<<endl;
    }
    return 0;
}