import std.conv, std.stdio, std.string;

immutable INF = 10L^^18 + 1;

void main() {
	string[] tokens;
	tokens = readln.chomp.split(" ");
	const N = tokens[0].to!int;
	const M = tokens[1].to!long;
	tokens = readln.chomp.split(" ");
	auto A = new int[N];
	foreach (i; 0 .. N) {
		A[i] = tokens[i].to!int;
	}
	tokens = readln.chomp.split(" ");
	auto K = new long[N];
	foreach (i; 0 .. N) {
		K[i] = tokens[i].to!long;
	}
	
	const lim = A[$ - 1]^^2;
	auto dp = new long[lim + 1];
	dp[] = INF;
	dp[0] = 0;
	foreach (i; 0 .. N) {
		foreach (x; A[i] .. lim + 1) {
			if (dp[x] > dp[x - A[i]] + 1) {
				dp[x] = dp[x - A[i]] + 1;
			}
		}
	}
	long target = -M;
	foreach (i; 0 .. N) {
		target += A[i] * K[i];
	}
	long ans;
	if (target < 0) {
		ans = INF;
	} else if (target < lim) {
		ans = dp[cast(size_t)(target)];
	} else {
		const greed = ((target - lim) + A[$ - 1] - 1) / A[$ - 1];
		ans = greed + dp[cast(size_t)(target - A[$ - 1] * greed)];
	}
	if (ans >= INF) {
		writeln(-1);
	} else {
		writeln(ans);
	}
}