cf Strings of Power

http://codeforces.com/contest/318/problem/B

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;

char str[2000000];

int main()
{
    cin>>str;
    int k=strlen(str);
    __int64 t=0,ans=0;
    for(int i=0; i<k; i++)
    {
        if(str[i]=='h'&&str[i+1]=='e'&&str[i+2]=='a'&&str[i+3]=='v'&&str[i+4]=='y'&&i+4<k)
        {
            t++;
        }
        if(str[i]=='m'&&str[i+1]=='e'&&str[i+2]=='t'&&str[i+3]=='a'&&str[i+4]=='l'&&i+4<k)
        {
            ans+=t;
        }
    }
    cout<<ans<<endl;
    return 0;
}