import re

s = input()

ans = 0
c_op12 = 0
tr = str.maketrans('e', 'h', 'h')
while True:
    n = s.count('phnom')
    if n > 0:
        s = s.replace('phnom', 'penh').translate(tr)
        ans += n + 1
        c_op12 += 1
        if c_op12 == 2:
            match = re.findall('(phn(om)+)', s)
            if match:
                c = [(len(m[0])- 3) // 2 for m in match]
                ans += sum(c) + max(c)
            ans += 1 # 最後の操作2の分
            break
    elif 'h' in s or 'e' in s:
        s = s.translate(tr)
        ans += 1
    else:
        break
print(ans)