import re
import sys
# sys.stdin = open('c.txt')

s = input()

ans = 0
tr = str.maketrans('e', 'h', 'h')
c_op12 = 0
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:
                max_c = 0
                for m in match:
                    c = (len(m[0])-3)//2
                    ans += c
                    max_c = max(max_c, c)
                ans += max_c
            ans += 1 # 最後の操作2の分
            break
    else:
        if 'h' in s or 'e' in s:
            s = s.translate(tr)
            ans += 1
        else:
            break
print(ans)