#include <stdio.h>
#include <stdlib.h>

int main()
{
    int n;
    while (1) {
        scanf("%d", &n);
        if (n == 0)
            break;
        int a[10000] = { 0 }, b[10000] = { 0 }, i = 0;
        for (i = 0; i < n; i++)
            scanf("%d", &a[i]);
        for (i = 0; i < n; i++)
            scanf("%d", &b[i]);

        int x[60001] = { 0 }, y[60001] = { 0 }; /*用來暫存及排序用的陣列*/
        for (i = 0; i < n; i++) {
            x[a[i]]++;
            y[b[i]]++;
        }

        int j = 0, sum = 0, k;
        i = 0;
        while (sum < n) {
            sum += x[i];
            k = x[i];
            while (k-- > 0) {
                a[j] = i;
                j++;
            }
            i++;
        }
        i = 0;
        j = 0;
        sum = 0;
        while (sum < n) {
            sum += y[i];
            k = y[i];
            while (k-- > 0) {
                b[j] = i;
                j++;
            }
            i++;
        }

        sum = 0;
        i = 0;
        j = 0;
        while (i < n && j < n) {
            if (a[i] < b[j]) {
                sum++;
                j++;
                i++;
            } else {
                j++;
            }
        }

        printf("%d\n", sum);
    }
    return 0;
}