#include <bits/stdc++.h>

#define el '\n'
#define ll long long
#define ld long double

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

using namespace std;

void testCase() {
    int n, k;
    cin >> n >> k;

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

    int sol = 0;

    for (int msk = 0; msk < (1 << k); msk++) {
        int mn = 1e9;

        for (int i = 0; i < n; i++) {
            int curSol = 0;

            for (int bit = 0; bit < msk; bit++)
                curSol += (msk & (1 << bit) ? (a[i][bit] == 'T') : (a[i][bit] == 'F'));

            mn = min(mn, curSol);
        }

        sol = max(sol, mn);
    }

    cout << sol;
}

signed main() {
    Beevo

    int T = 1;
//    cin >> T;

    while (T--)
        testCase();

    return 0;
}