#include <iostream>
#include <cmath>
#include <cstdlib>
using namespace std;

int main (void){
    int n, s, r;
    int unisteni[20], rezervni[20];
    cin >>n>>s>>r;
    int i;
    int temp;
    for (i=1;i<=s;i++){
        cin >>unisteni[i];
    }
    for (i=1;i<=r;i++){
        cin >>rezervni[i];
    }
    int j, c;
    c=0;
    for (i=1;i<=s;i++)
        for (j=1;j<=r;j++)
            if (abs(unisteni[i]-rezervni[j])<=1){
               c++;
               rezervni[j]=150;
               break;
            }
    cout <<s-c;
    cin >>i;
return 0;
}