#include<stdio.h>
/*
Binary Search
2019. 4/30
*/

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 = 1; i < q; i++){
        scanf("%d", &k);
        if (binarySearch(k)) sum++;
    }
    printf("%d\n", sum);

    return 0;
}

