func main()
	var s: []char :: cui@input()
	do s :: s.sub(0, s.findStr("pain", -1) + 1)
	
	var ans: int :: -1
	for i(0, ^s - 3)
		if(s[i] = 'p' & s[i + 1] = 'o' & s[i + 2] = 'n')
			do ans :+ 1
		end if
	end for
	if(ans = 0)
		do ans :: -1
	end if
	do cui@print("\{ans}\n")
end func