func main()
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var a: []int :: #[m]int
	for(1, n)
		var s: []char :: cui@input()
		for i(0, m - 1)
			if(s[i] = 'x')
				do a[i] :+ 1
			end if
		end for
	end for
	
	do a.sort()
	do a.reverse()
	
	var ans: int :: a[0] + 1
	do cui@print("\{ans}\n")
end func