#![allow(unused_imports, dead_code, unused_macros, unused_variables, non_snake_case, unused_parens)]
use proconio::{input,marker::{Bytes, Chars, Usize1,Isize1}};
use std::ops::*;
use std::cmp::*;
use std::mem::swap;
use std::collections::*;
use itertools::*;
use num::integer::*;

const MOD:u64 = 1_000_000_007;
const INF:i64 = 0x3fff_ffff_ffff_ffff;
const YES:&str="Yes";const NO:&str="No";macro_rules!yesno{($var:expr) => {if $var{println!("{}",YES);}else{println!("{}",NO);}}}

macro_rules! min {($a:expr $(,)*) => {{$a}};($a:expr, $b:expr $(,)*) => {{std::cmp::min($a, $b)}};($a:expr, $($rest:expr),+ $(,)*) => {{std::cmp::min($a, min!($($rest),+))}};}
macro_rules! max {($a:expr $(,)*) => {{$a}};($a:expr, $b:expr $(,)*) => {{std::cmp::max($a, $b)}};($a:expr, $($rest:expr),+ $(,)*) => {{std::cmp::max($a, max!($($rest),+))}};}
macro_rules! chmin {($base:expr, $($cmps:expr),+ $(,)*) => {{let cmp_min = min!($($cmps),+);if $base > cmp_min {$base = cmp_min;true} else {false}}};}
macro_rules! chmax {($base:expr, $($cmps:expr),+ $(,)*) => {{let cmp_max = max!($($cmps),+);if $base < cmp_max {$base = cmp_max;true} else {false}}};}
macro_rules! mulvec {($x:expr; $s:expr) => {vec![$x; $s]};($x:expr; $s0:expr; $( $s:expr );+) => {mulvec![vec![$x; $s0]; $( $s );+ ]};}
macro_rules! outputln {($var:expr)=>{println!("{}",$var)};($var:expr,$($vars:expr),+)=>{print!("{} ",$var);outputln!($($vars),+);};}
macro_rules! debug {($($a:expr),* $(,)*) => {eprintln!(concat!($("| ",stringify!($a), "={:?} "),*, "|"),$(&$a),*);};}




fn main() {
	input! {
		N: usize,
		M: usize,
		S: [Chars; N],
	}
	let mut cnt = vec![0; M];
	for i in 0..M {
		for s in &S {
			if s[i] == 'o' {
				cnt[i] += 1;
			}
		}
		
	}
	let mut ans = 0;
	for s in &S {
		let mut ok = true;
		let mut c = 0;
		for i in 0..M {
			if s[i] == 'o' {
				c += 1;
				if cnt[i] != 1 {
					ok = false;
				}
			}
		}
		if ok && c > 0 {
			ans += 1;
		}
	}
	outputln!(ans);
}