package Practice;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.util.StringTokenizer;

public class B1969 { //DNA

static int N, M;

static int[] DNA;

public static void main(String[] args) throws Exception {

// TODO Auto-generated method stub

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

StringBuilder sb = new StringBuilder();

StringTokenizer st = new StringTokenizer(br.readLine());

N = Integer.parseInt(st.nextToken());

M = Integer.parseInt(st.nextToken());

String[] s = new String[N];

for(int i = 0; i < N; i++) s[i] = br.readLine();

char[] printDNA = new char[4];

printDNA[0] = 'A';

printDNA[1] = 'C';

printDNA[2] = 'G';

printDNA[3] = 'T';

int dis = 0;

for(int i = 0; i < M; i++) {

DNA = new int[4]; //0 : A, 1 : C, 2 : G, 3 : T

for(int j = 0; j < N; j++) {

char c = s[j].charAt(i);

Hamming(c);

}

int index = Distance();

sb.append(printDNA[index]);

dis += N - DNA[index];

}

sb.append('\n').append(dis);

System.out.println(sb);

}

static void Hamming(char c) {

if(c == 'A') DNA[0]++;

else if(c == 'C') DNA[1]++;

else if(c == 'G') DNA[2]++;

else DNA[3]++;

}

static int Distance() {

int max = Integer.MIN_VALUE, index = 0;

for(int i = 0; i < 4; i++) {

if(max < DNA[i]) {

index = i;

max = DNA[i];

}

}

return index;

}

}