#include <bits/stdc++.h>

using namespace std;

#define int long long
#define ld long double
#define el '\n'
#define fi first
#define se second

#define Nine_seconds ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);


void run_case(int tc) {
    int n, k;
    cin >> n >> k;

    string s[n];
    for (int i = 0; i < n; i++)
        cin >> s[i];

    int ans = -1;
    for (int i = 0; i < (1 << k); i++) {
        int mn = 1e9;
        for (int j = 0; j < n; j++) {
            int tmp = 0;
            for (int cur = 0; cur < k; cur++) {
                if (s[j][cur] == 'T' && ((1 << cur) & i) || s[j][cur] == 'F' && !((1 << cur) & i))
                    tmp++;
            }
            mn = min(mn, tmp);
        }
        ans = max(ans, mn);
    }

    cout << ans;
}


int32_t main() {
    Nine_seconds        /*Turn Off for Interactive Problems*/

    int _t = 1;
    //cin >> _t;
    for (int i = 1; i <= _t; i++) {
        run_case(i);
    }

}