#include <iostream>
using namespace std;
string a[114514];
int n,m,sum;
void be() // init & input
{
	cin >> n >> m;
	for(int i = 1;i <= n;i++)
	{
		cin >> a[i];
	}
	return ;
}
void kin() // programming
{
	for(int i = 1;i <= n;i++)
	{
		for(int j = 0;j < m - 3;j++)
		{
			
			string he = "";
			for(int k = j;k - j <= 3;k++)
			{
				he += a[i][k];
			}
//			cout << he << endl;
			if(he == "hehe" || he == "eheh")
			{
				sum++;
			}
		}
	}
	return ;
}
void ei() // output
{
	cout << sum << endl;
	return ;
}
int main()
{
	be();
	kin();
	ei();
	return 0;
}