#include<stdio.h>

int A[100000], n;

/*２分探索*/
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;
        else 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;
}
