#![allow(non_snake_case, unused_imports)]

use std::cmp::{min, max};
use std::collections::{BinaryHeap, Bound, HashMap, HashSet, VecDeque};
use std::hash::Hash;
use std::ops::RangeBounds;
use ac_library::{Additive, Min, Segtree};
use proconio::{input, marker::Usize1, marker::Chars};
use itertools::Itertools;

#[allow(unused_macros)]
macro_rules! d {
    ( $( $x:expr ),* $(,)? ) => {
        eprintln!(
            concat!( $( stringify!($x), "={:?} " ),* ),
            $( $x ),*
        );
    };
}

#[allow(dead_code)]
fn yn(b: bool) -> &'static str {
    if b { "Yes" } else { "No" }
}

fn main() {
    input! {
        N: usize,
        M: usize,
        SS: [String; N],
    }

    let mut xs = vec![0; M];
    for s in SS.iter() {
        for (i, c) in s.chars().enumerate() {
            if c == 'o' {
                xs[i] += 1;
            }
        }
    }

    let mut ans = 0;
    for s in SS.iter() {
        if !s.contains('o') { continue }

        let b = s.chars()
            .zip(xs.iter())
            .all(|(c, &x)| {
                match c {
                    'o' => x == 1,
                    'x' => true,
                    _ => unreachable!()
                }
            });

        if b {
            ans += 1;
        }
    }

    println!("{}", ans);
}