#include<iostream>
using namespace std;
main(){
	int a[4]={},b=1e7,i=3;
	for(char s;cin>>s;a[s-116?s-114?s-101?3:2:1:0]++);
	for(;i--;)b>a[i]/(i-2?1:2)?b=a[i]/(i-2?1:2):0;
	cout<<b<<endl;
}