def max_operations(s):
    count = 0
    prev = None
    while True:
        # Apply operation 1 as many times as possible
        cnt1 = 0
        new_s = []
        i = 0
        n = len(s)
        while i <= n - 5:
            if s[i:i+5] == 'phnom':
                new_s.append('penh')
                cnt1 += 1
                i += 5
            else:
                new_s.append(s[i])
                i += 1
        # Add remaining characters
        while i < n:
            new_s.append(s[i])
            i += 1
        if cnt1 > 0:
            count += cnt1
            s = ''.join(new_s)
            prev = None
            continue  # go back to check operation 1 again
        
        # Apply operation 2 once if possible
        # Check if applying operation 2 changes the string
        # Step 1: remove all 'h's
        temp = s.replace('h', '')
        # Step 2: replace all 'e's with 'h's
        temp2 = temp.replace('e', 'h')
        if temp2 != s:
            count += 1
            s = temp2
            prev = s
        else:
            break  # no more operations possible
    return count

s = input().strip()
print(max_operations(s))