import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;

/**
 * Built using CHelper plug-in Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputReader in = new InputReader(System.in);
		PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)), true);
		TaskB solver = new TaskB();
		solver.solve(1, in, out);
		out.flush();
		out.close();
	}
}

class Pair<A, B> {
	A first;
	B second;

	Pair(A first, B second) {
		this.first = first;
		this.second = second;
	}

}

class TaskB {
	int INF = (int) 1e3 + 5;
	int mod = (int) 1e9 + 7;

	public void solve(int testNumber, InputReader in, PrintWriter pw) {
		int N = in.nextInt();
		int K = in.nextInt();
		int dp[] = new int[K + 1];
		dp[0] = 1;
		for (int i = 0; i < N; i++) {
			int upto = in.nextInt();
			for (int used = K; used >= 0; used--) {
				for (int here = 1; here <= Math.min(upto, K - used); here++) {
					dp[used + here] += dp[used];
				}
			}

		}
		pw.println(dp[K]);

//		for (int i = 0; i < N; i++) {
//			pw.println(Arrays.toString(dp[i]));
//		}
	}

	boolean FirstRow_Col(Pair<Integer, Integer> pair) {
		return pair.first == 0 || pair.second == 0;
	}

	int __gcd(int a, int b) {
		if (b == 0)
			return a;
		return __gcd(b, a % b);

	}

	public int getInt(int num) {
		int ret = -1;
		switch (num) {
		case 0:
			ret = 6;
			break;
		case 1:
			ret = 2;
			break;
		case 2:
			ret = 5;
			break;
		case 3:
			ret = 5;
			break;
		case 4:
			ret = 4;
			break;
		case 5:
			ret = 5;
			break;
		case 6:
			ret = 6;
			break;
		case 7:
			ret = 3;
			break;
		case 8:
			ret = 7;
			break;
		case 9:
			ret = 6;
			break;
		}
		return ret;
	}

	public int isPow(long num) {
		int count = 0;
		while (num > 0) {
			num /= 2;
			count++;
		}
		return count;
	}
}

class InputReader {
	BufferedReader br;
	StringTokenizer st;

	public InputReader(InputStream in) {
		br = new BufferedReader(new InputStreamReader(in));
		st = null;
	}

	public String next() {
		while (st == null || !st.hasMoreTokens()) {
			try {
				st = new StringTokenizer(br.readLine());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return st.nextToken();
	}

	public int nextInt() {
		return Integer.parseInt(next());
	}

	public long nextLong() {
		return Long.parseLong(next());
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}
}
