import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
 class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner x = new Scanner(System.in);
		while(x.hasNext()){
int n=x.nextInt();
int[]y=new int[n];
for(int i=0;i<n;i++){
	y[i]=x.nextInt();
 
 
	}
int val=0;
int max=0;
for(int j=0;j<n-1;j++){
 
	if(y[j]<y[j+1]){
 
		val=y[j+1]-y[j];
		if(val>max){
 
			max=val;
		}
	}
 
		}
 
		// your code goes here
		if(max==0){
					System.out.println(1);
 
		}else{
 
					System.out.println(max);
 
		}
	}
}
}

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

Ngo1IDIgMSA0IDUgMwozCjEgMSAxCjQKNCAzIDIgMQ==

6
5 2 1 4 5 3
3
1 1 1
4
4 3 2 1