#include<algorithm>
#include<iostream>
using namespace std;

int a[1001], b[1002]; int bun[1002], n,m;

int main(void){

    cin>>n>>m;
    int i;

    for(i=1;i<=n;i++) cin>>a[i];
    for(i=1;i<=m;i++) cin>>b[i];
    sort(a+1,a+n+1);
    sort(b+1,b+m+1); int curr;
    curr=m; a[0]=a[1]-1;
    for(i=1;i<=n;i++){

        if (a[i] != a[i-1]) bun[i]=a[i]-b[curr];
        else {
            while(curr>1&& b[curr]==b[curr-1]) curr--;
            if (curr>1) curr--;
            bun[i]=a[i]-b[curr];
        }
    }
    int x=0;bun[0]=bun[1]-1;
    for(i=1;i<=n;i++){

        if (bun[i] !=bun[i-1]) x++;
    }
    cout<<x<<"\n";
    for(i=1;i<=n;i++) cout<<bun[i]<<" ";
    return 0;


}