#include <bits/stdc++.h>

#define el '\n'
#define Beevo ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

typedef long long ll;
typedef long double ld;

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

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

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

    int dp[n][l];
    for (int i = 0; i + 1 < n; i++) {
        int sm = l;
        for (int j = l - 1; j >= 0; j--) {
            if (s[i][j] < s[i + 1][j])
                sm = j;
            else if (s[i][j] > s[i + 1][j])
                sm = l;

            dp[i][j] = sm;
        }
    }

    int a = 0, b = l - 1;
    for (int j = 0; j < l; j++) {
        int mx = 0;
        for (int i = 0; i + 1 < n; i++)
            mx = max(mx, dp[i][j]);

        if (mx != l && mx - j < b - a)
            a = j, b = mx;
    }

    cout << a + 1 << ' ' << b + 1;
}

signed main() {
    Beevo

    int t = 1;
//    cin >> t;

    while (t--)
        testCase();
}