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

int main (void){
    int n, s, r;
    int slom[11], posudba[11];
   cin >>n>>s>>r;
    int i;
    int temp;
    for (i=1;i<=s;i++){
        cin >>slom[i];
    }
    for (i=1;i<=r;i++){
        cin >>posudba[i];
    }
    int j, c;
    c=0;
    for (i=1;i<=s;i++)
        for (j=1;j<=r;j++)
            if (abs(slom[i]-posudba[j])<=1){
               c++;
               posudba[j]=150;
               break;
            }
    cout <<s-c;
    cin >>i;
return 0;
}