buy-and-sell-once/src/main/java/Solution.java

import java.util.*;

class Solution {
	
	public static void main( String[] args ) {
		// read values with in.next...() methods
		var prices = new Scanner( System.in ).tokens()
				.mapToInt( Integer::valueOf )
				.toArray();
		
		// code your solution here
		int maxProfit = 0;
		for ( int index = 0; index < prices.length; index++ ) {
			var currentPrice = prices[index];
			
			for ( int rem = index + 1; rem < prices.length; rem++ ) {
				var futurePrice = prices[rem];
				var profit = futurePrice - currentPrice;
				maxProfit = Math.max( profit, maxProfit );
			}
		}
		
		// Write result with System.out.println()
		System.out.println( maxProfit );
	}
	
}