Problem: I’m planning to have a party on my birthday. Many of my friends will come to the party. Some of them will come with one or more pieces of cakes, but it is not certain if the number of the cakes is a multiple of the number of people coming.

I wish to enjoy the cakes equally among the partiers. So, I decided to apply the following rules. First, all the party attendants are given the same number of cakes. If some remainder occurs, a piece goes on a priority basis to the party host (that’s me!). How many pieces of cake can I enjoy?

Given the number of my friends and cake information, make a program to calculate how many pieces of cake I can enjoy. Note that I am not counted in the number of my friends.



Input

The input is given in the following format.


$N$ $C$
$p_1$ $p_2$ ... $p_C$


The first line provides the number of my friends $N$ ($1 \leq N \leq 100$) and the number of those among them who brought one or more pieces of cake with them $C$ ($1 \leq C \leq N$). The second line provides an array of integers $p_i$ ($1 \leq p_i \leq100$), each of which shows the number of cakes of the $i$-th friend of mine who was willing to come up with one or more pieces of cake.

Output

Output the number of cakes I can enjoy.

Examples

Input

5 4
5 5 6 5


Output

4


Input

7 5
8 8 8 8 8


Output

5


Input

100 3
3 3 3


Output

1

Solution (in JAVA):

Solution:
import java.util.*;
import java.util.stream.*;
import java.io.*;
import java.math.*;

public class Main {

	static void solve (FastScanner in, PrintWriter out, Methods ms) {
		
		int n = in.nextInt(), m = in.nextInt();
		int cake = 0;
		for (int i=0; i<m; i++) cake += in.nextInt();
		out.println(cake%(n+1)==0? cake/(n+1) : cake/(n+1)+1);
		
	}
	


	public static void main(String[] args) {
		FastScanner in = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		Methods ms = new Methods();
		solve(in, out, ms);
		in.close();
		out.close();
	}

	static class Methods {

		public void print (Object... ar) {System.out.println(Arrays.deepToString(ar));}

		public int max (int... ar) {Arrays.sort(ar); return ar[ar.length-1];}

		public int min (int... ar) {Arrays.sort(ar); return ar[0];}

		public long gcd (long a, long b) {return b>0?gcd(b,a%b):a;}

		public long lcm (long a, long b) {return a/gcd(a,b)*b;}

		public long factorial (int i) {
			if (i==1) return 1;
			else return i*factorial(i-1);
		}

		public int manhat (int x1, int y1, int x2, int y2) {
			return Math.abs(x1-x2)+Math.abs(y1-y2);
		}

		public double euclid (double x1, double y1, double x2, double y2) {
			return Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
		}

		public boolean isPrime (int n) {
			if (n==2) return true;
			if (n<2 || n%2==0) return false;
			for (int i=3; i<=Math.sqrt(n); i+=2) if(n%i==0) return false;
			return true;
		}

	}

	static class FastScanner {

		private InputStream in;
		private byte[] buffer = new byte[1024];
		private  int length = 0, p = 0;

		public FastScanner (InputStream stream) {
			in = stream;
		}

		public boolean hasNextByte () {
			if (p < length) return true;
			else {
				p = 0;
				try {length = in.read(buffer);}
				catch (Exception e) {e.printStackTrace();}
				if (length <= 0) return false;
			}
			return true;
		}

		public int readByte () {
			if (hasNextByte() == true) return buffer[p++];
			return -1;
		}

		public boolean isPrintable (int n) {return 33<=n&&n<=126;}

		public void skip () {
			while (hasNextByte() && !isPrintable(buffer[p])) p++;
		}

		public boolean hasNext () {skip(); return hasNextByte();}

		public String next () {
			if (!hasNext()) throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int t = readByte();
			while (isPrintable(t)) {
				sb.appendCodePoint(t);
				t = readByte();
			}
			return sb.toString();
		}

		public String[] nextArray (int n) {
			String[] ar = new String[n];
			for (int i=0; i<n; i++) ar[i] = next();
			return ar;
		}

		public int nextInt () {return Math.toIntExact(nextLong());}

		public int[] nextIntArray (int n) {
			int[] ar = new int[n];
			for (int i=0; i<n; i++) ar[i] = nextInt();
			return ar;
		}

		public long nextLong () {
			if (!hasNext()) throw new NoSuchElementException();
			boolean minus = false;
			int temp = readByte();
			if (temp == '-') {
				minus = true;
				temp = readByte();
			}
			if (temp<'0' || '9'<temp) throw new NumberFormatException();
			long n = 0;
			while (isPrintable(temp)) {
				if ('0'<=temp && temp<='9') {
					n *= 10;
					n += temp - '0';
				}
				else throw new NumberFormatException();
				temp = readByte();
			}
			return minus? -n : n;
		}

		public long[] nextLongArray (int n) {
			long[] ar = new long[n];
			for (int i=0; i<n; i++) ar[i] = nextLong();
			return ar;
		}

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

		public double[] nextDoubleArray (int n) {
			double[] ar = new double[n];
			for (int i=0; i<n; i++) ar[i] = nextDouble();
			return ar;
		}

		public void close () {
			try {in.close();}
			catch(Exception e){}
		}

	}

}