#include<stdio.h>

int A[1000000], 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;
     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;
}
