func main()
	var ss: [][]char :: cui@input().split(" ")
	var n: int :: ss[0].toInt(&)
	var m: int :: ss[1].toInt(&)
	var ans: int :: 0
	for(1, n)
		var s: []char :: cui@input()
		for i(0, m - 1)
			do ans :+ s[i] = 'R' ?(0, 1)
		end for
	end for
	do cui@print("\{ans}\n")
end func