#include <cstdio>
#include <iostream>
#include <cstring>

using namespace std ;

int n, s, r, a, sol = 0 ;
bool kajak [ 50 ] ;

int main ( void ) {
    scanf ( "%d%d%d", &n, &s, &r ) ;
    memset ( kajak, true, sizeof ( kajak ) ) ;
    for ( int i = 0 ; i < s ; ++i ) {
        scanf ( "%d", &a ) ;
        --a;
        kajak [ a ] = false ;
    }
    for ( int i = 0 ; i < r ; ++i ) {
        scanf ( "%d", &a ) ;
        --a;
        if ( a-1>-1 && !kajak [ a-1 ] ) {
            kajak [ a-1 ] = true ;
            a = -200 ;
        }
        if ( a != -200 && a+1 < n && !kajak [ a+1 ] )
           kajak [ a+1 ] = true ;
    }
    for ( int i = 0 ; i < n ; ++i )
        if ( !kajak [ i ] ) ++sol ;
    printf ( "%d\n", sol ) ;
    return 0 ;
}