def max_operations(S):
    current = S
    count = 0
    while True:
        # Apply all possible operation 1
        new_str = current
        while True:
            index = new_str.find('phnom')
            if index == -1:
                break
            new_str = new_str[:index] + 'penh' + new_str[index+5:]
            count += 1
        if new_str == current:
            # No change in operation 1, try operation 2
            # Apply operation 2
            temp = new_str.replace('h', '')
            temp = temp.replace('e', 'h')
            if temp != new_str:
                count += 1
                new_str = temp
            else:
                # No change in operation 2, break
                break
        current = new_str
    return count

# Read input
S = input().strip()

# Compute result
result = max_operations(S)

# Output the result
print(result)