S = input().strip()
ans = 0

while True:
    # Apply operation1 as much as possible
    operation1_done = False
    while True:
        # Count and replace all occurrences of 'phnom'
        new_S = []
        i = 0
        count_op1 = 0
        len_S = len(S)
        while i <= len_S - 5:
            if S[i:i+5] == 'phnom':
                new_S.append('penh')
                count_op1 += 1
                i += 5
            else:
                new_S.append(S[i])
                i += 1
        # Add remaining characters
        new_S.extend(S[i:])
        new_S_str = ''.join(new_S)
        if count_op1 == 0:
            break
        ans += count_op1
        S = new_S_str
        operation1_done = True
    
    if operation1_done:
        # Check if new S contains 'phnom' again after replacing
        if 'phnom' in S:
            continue  # Restart the loop to process operation1 again
        else:
            operation1_done = False

    # Apply operation2 as many times as possible
    applied_op2 = False
    while True:
        s1 = S.replace('h', '').replace('e', 'h')
        if s1 == S:
            break  # No change, can't apply
        # Apply once
        ans += 1
        applied_op2 = True
        prev_S = S
        S = s1
        # Check after first application
        if 'phnom' in S:
            break  # Need to restart loop for operation1
        # Apply second time if possible
        s2 = S.replace('h', '').replace('e', 'h')
        if s2 == S:
            break  # No further change
        ans += 1
        S = s2
        # Check after second application
        if 'phnom' in S:
            break
    if applied_op2 and 'phnom' in S:
        continue  # Restart loop for operation1
    else:
        break  # No more possible operations

print(ans)