s=input()
n = 0
num = -1
while num < n:
    num = n
    fi = s
    fd = s.find('phnom')
    if fd > -1:
        s = s.replace('phnom', 'penh', 1)
        n += 1
        if s == fi:
            n -= 1
            s = fi
    fd = s.find('h')
    if fd > -1:
        s = s.replace('h', '')
        s = s.replace('e', 'h')
        n += 1
        if s == fi:
            n -= 1
            s = fi
print(n)