#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
const int M = 3e5 + 10;
long long n, m, k, b[M], sum[N], a[N], p[M];
long long read() {
	long long f = 1, x = 0;
	char c = getchar();
	while (c < '0' || c > '9') {
		if (c == '-')f = -1;
		c = getchar();
	}
	while (c >= '0' && c <= '9') {
		x = x * 10 + c - '0';
		c = getchar();
	}
	return f * x;
}
void write(long long x) {
	if (x < 0) {
		putchar('-');
		x = -x;
	}
	if (x > 9)write(x / 10);
	putchar(x % 10 + '0');
}
map<long long, long long>ma;
int main() {
	long long tot = 1;
	n = read();
	m = read();
	k = read();
	for (int i = 1; i <= m; i++)b[i] = read();
	sum[0] = -k + 1;
	for (int i = 1; i <= n; i++) {
		a[i] = read();
		sum[i] = sum[i - 1] + a[i];
		sum[i] %= k;
		p[i] = p[i - 1];
		if (i == b[tot]) {
			if (sum[i] == 1)p[i]++;
			tot++;
		}
	}
	long long ans = p[n];
	tot = m;
	for (int i = n; i >= 1; i--) {
		if (i == b[tot]) {
			ma[sum[b[tot]]]++;
			tot--;
		}
		a[i] %= k;
		ans = max(ans, ma[a[i]] + p[i - 1]);
	}
	write(ans);
	return 0;
}