text = input()
counter = 0
convert_text_to_lower = list(text.lower())
i = 1
check_len = len(convert_text_to_lower)
for word in convert_text_to_lower:
    if check_len - 2 == i:
        break
    check_word = word + convert_text_to_lower[i] + convert_text_to_lower[i + 1] + convert_text_to_lower[i + 2]
    i += 1
    if "sand" in check_word:
        counter += 1

    if "fish" in check_word:
        counter += 1

check_word = ""
i = 1
for word in convert_text_to_lower:
    if check_len - 1 == i:
        break
    check_word = word + convert_text_to_lower[i] + convert_text_to_lower[i + 1]
    i += 1
    if "sun" in check_word:
        counter += 1

check_word = ""
i = 1
for word in convert_text_to_lower:
    if check_len - 3 == i:
        break

    check_word = word + convert_text_to_lower[i] + convert_text_to_lower[i + 1] + convert_text_to_lower[i + 2] + \
                 convert_text_to_lower[i + 3]
    i += 1
    if "water" in check_word:
        counter += 1

print(counter)