#include <stdlib.h>
#include <stdio.h>
void countSort(char *arr[], int n, int k, int pos){
    char result[n][k];
    int val;
    char count[10] = { 0 };
    for(int i = 0; i < n; i++){
        count[arr[i][pos] - '0']++;
    }
    for(int i = 1; i < 10; i++){
        count[i] += count[i - 1];
    }

    /*for(int i = 0; i < 10; i++){
        printf("%d ", count[i]);
    }*/

    for(int i = n - 1; i >= 0; i--){
        for(int j = 0; j < k; j++) {
            result[count[arr[i][pos]- '0'] - 1][j] = arr[i][j];
        }
        count[ arr[i][pos] - '0' ]--;
    }
    for(int i = 0; i < n; i++){
        for(int j = 0; j < k; j++){
            arr[i][j] = result[i][j];
        }
    }


}

int main() {
    int n;
    int k;
    scanf("%d", &n);
    scanf("%d", &k);
    char** arr = (char **)malloc((n + 1) * sizeof(char *));
    for(int i = 0; i < n; i++){
        arr[i] = (char *)malloc((k + 1) * sizeof(char));
    }
    for(int i = 0; i < n; i++){
        scanf("%s", arr[i]);
    }
    for(int i = k - 1; i >= 0; i--) {
        countSort(arr, n, k, i);
    }
    for (int i = 0; i < n; i++) {
        printf("\n%s", arr[i]);
    }

}