Problem: There are N observatories in AtCoder Hill, called Obs. 1, Obs. 2, ..., Obs. N. The elevation of Obs. i is H_i. There are also M roads, each connecting two different observatories. Road j connects Obs. A_j and Obs. B_j.

Obs. i is said to be good when its elevation is higher than those of all observatories that can be reached from Obs. i using just one road. Note that Obs. i is also good when no observatory can be reached from Obs. i using just one road.

How many good observatories are there?

Constraints

* 2 \leq N \leq 10^5
* 1 \leq M \leq 10^5
* 1 \leq H_i \leq 10^9
* 1 \leq A_i,B_i \leq N
* A_i \neq B_i
* Multiple roads may connect the same pair of observatories.
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N M
H_1 H_2 ... H_N
A_1 B_1
A_2 B_2
:
A_M B_M


Output

Print the number of good observatories.

Examples

Input

4 3
1 2 3 4
1 3
2 3
2 4


Output

2


Input

6 5
8 6 9 1 2 1
1 3
4 2
4 3
4 6
4 6


Output

3

Solution (in JAVA):

Solution:
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.HashSet;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int n = sc.nextInt(), m = sc.nextInt();
        int []v = new int[n + 1];
        int []c = new int[n + 1];
        for(int i = 1; i <= n; ++i) {
            v[i] = sc.nextInt();
        }

        for(int i = 1; i <= m; ++i){
            int a, b; 
            a = sc.nextInt();
            b = sc.nextInt();
            c[a] --;
            if(v[b] < v[a]){
                c[a] ++;
            }
            c[b] --;
            if(v[b] > v[a]){
                c[b] ++;
            }
        }
        int ans = 0;
        for(int i = 1; i <= n; ++i) {
            ans += (c[i] == 0) ? 1 : 0;
        }   
        System.out.println(ans);
    }    
}