#include <stdio.h>

int A[1000000];
int n;

int binarySearch(int key){
    int left = 0;
    int right = n;
    int mid;
    
    while(left < right) {
        mid = (left + right) /2 ;
        if (key == A[mid]) return 1;
        if (key > A[mid]) left = mid + 1;
        if (key < A[mid]) right = mid;
    }
    return 0;
}

int main(){
    int i, q, k, sum =0;
    
    scanf("%d", &n);
    for(i = 0; i < n; i++){
        scanf("%d",&A[i]);
    }

    scanf("%d",&q);
    for (i =0; i <q; i++) {
        scanf("%d",&k);
        if (binarySearch(k)) sum++;
    }
    printf("%d\n",sum);
    return 0;
}

