import sys
sys.setrecursionlimit(10**6)

def D(*a, **kwa):
    print(*a, file=sys.stderr, **kwa)

pm = 'phnom'
ph = 'penh'
can_op1 = lambda s: pm in s
can_op2 = lambda s: 'h' in s or 'e' in s

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

def solve(op, s, hist):
    if op == 1:
        if can_op1(s):
            s = op1(s)
            hist = hist + '1'
            return solve(2, s, hist)
        else:
            return hist
    else:
        if can_op2(s):
            s = op2(s)
            hist = hist + '2'
            h1 = solve(1, s, hist)
            h2 = '' if hist[-2:] == '22' else solve(2, s, hist)
            return h1 if len(h1) > len(h2) else h2
        else:
            return hist

S = input()

ans = 0
for i in range(1, 2+1):
    hist = solve(i, S, '')
    # D(hist)
    ans = max(ans, len(hist))

print(ans)