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

tr = str.maketrans('e', 'h', 'h')
op1 = lambda s: s.replace('phnom', 'penh')
op2 = lambda s: s.translate(tr)

s = input()

op = 1
cnt_op1 = cnt_op2 = 0
cnt_op1_op1 = 0
while True:
    if op == 1:
        before = len(s)
        s = op1(s)
        after = len(s)
        if after < before:
            cnt_op1 += before - after
            s = op2(s)
            cnt_op2 += 1
            cnt_op1_op1 += 1
            if cnt_op1_op1 == 2:
                match = re.findall('(phn(om)+)', s)
                if match:
                    max_c = 0
                    for m in match:
                        c = (len(m[0])-3)//2
                        cnt_op1 += c
                        max_c = max(max_c, c)
                    cnt_op2 += max_c
                cnt_op2 += 1
                break
        else:
            op = 2
    else:
        before = len(s)
        s = op2(s)
        after = len(s)
        if after < before:
            cnt_op2 += 1
            op = 1
        else:
            break

print(cnt_op1 + cnt_op2)