#include <cstdio>
#include <iostream>
#include <fstream>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <string>
#include <ctime>
#include <cassert>
#include <utility>

using namespace std;

#define MAXN 1024

int N, M;
int A[MAXN];
int B[MAXN];
vector<int> C;
vector<int> G[MAXN];
bool v[MAXN];
int st[MAXN * MAXN], dr[MAXN * MAXN];

bool pairup(int node) {
    if(v[node]) return false;
    v[node] = true;
    
    for(vector<int> :: iterator it = G[node].begin(); it != G[node].end(); it++)
        if(st[*it] == -1) {
            st[*it] = node;
            dr[node] = *it;
            return true;
        }
    
    for(vector<int> :: iterator it = G[node].begin(); it != G[node].end(); it++)
        if(pairup(st[*it])) {
            st[*it] = node;
            dr[node] = *it;
            return true;
        }
    
    return false;
}

int main() {
//	freopen("date.in", "r", stdin);
//	freopen("date.out","w", stdout);
	
	scanf("%d %d", &N, &M);
	for(int i = 0; i < N; i++)
        scanf("%d", &A[i]);
    for(int i = 0; i < M; i++)
        scanf("%d", &B[i]);
    
    for(int i = 0; i < N; i++) {
        C.push_back(A[i]);
        for(int j = 0; j < M; j++)
            C.push_back(A[i] - B[j]);
    }
    sort(C.begin(), C.end());
    C.resize(unique(C.begin(), C.end()) - C.begin());
    
    for(int i = 0; i < N; i++) {
        G[i].push_back( lower_bound(C.begin(), C.end(), A[i]) - C.begin() );
        for(int j = 0; j < M; j++)
            G[i].push_back( lower_bound(C.begin(), C.end(), A[i] - B[j]) - C.begin() );
    }
    
    int dim = max(N, (int)C.size());
    for(int i = 0; i < dim; i++) {
        st[i] = dr[i] = -1;
    }
    
    bool ok = false;
    int match = 0;
    while(!ok) {
        ok = true;
        memset(v, false, sizeof(v));
        for(int i = 0; i < N; i++)
            if(dr[i] == -1 && pairup(i)) {
                ok = false;
                match++;
            }
    }
	
//	bool first = true;
//	for(int i = 0; i < (int)C.size(); i++)
//        if(st[i] != -1) {
//            if(!first)
//                printf(" ");
//            first = false;
//            printf("%d", C[i]);
//        }
//    printf("\n");
    printf("%d\n", match);
    
    for(int i = 0; i < N; i++) {
        int crt;
        if(dr[i] == -1)
            crt = A[i];
        else
            crt = C[dr[i]];
        
        if(i > 0)
            printf(" ");
        printf("%d", crt);
    }
    printf("\n");
	
	return 0;
}