Problem:
Score : 300 points

Problem Statement

In a flower bed, there are N flowers, numbered 1,2,......,N. Initially, the heights of all flowers are 0.
You are given a sequence h=\{h_1,h_2,h_3,......\} as input. You would like to change the height of Flower k to h_k for all k (1 \leq k \leq N), by repeating the following "watering" operation:

Specify integers l and r. Increase the height of Flower x by 1 for all x such that l \leq x \leq r.

Find the minimum number of watering operations required to satisfy the condition.

Constraints

1 \leq N \leq 100

0 \leq h_i \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
h_1 h_2 h_3 ...... h_N

Output

Print the minimum number of watering operations required to satisfy the condition.

Sample Input 1

4
1 2 2 1

Sample Output 1

2

The minimum number of watering operations required is 2.
One way to achieve it is:

Perform the operation with (l,r)=(1,3).

Perform the operation with (l,r)=(2,4).

Sample Input 2

5
3 1 2 3 1

Sample Output 2

5

Sample Input 3

8
4 23 75 0 23 96 50 100

Sample Output 3

221

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int a = Integer.parseInt(sc.nextLine());
		int b[] = new int[a];
		int minimum = 0;
		int flower[] = new int[a];
//		populate input
		String readline = sc.nextLine();
		String[] test = readline.split(" ");
		for (int i = 0; i < a; i++) {
			flower[i] = 0;
			b[i] = Integer.parseInt(test[i]);
		}
		boolean flag = true;
		while (flag) {
			int i = 0;
			int j = 0;
			while (j < a)
				if (flower[i + j] < b[i + j]) {// if less
					flower[i + j] += 1;// +1 here
					j = j + 1;// increase j
					if (j == a)
						minimum += 1;
				} else if (flower[i + j] == b[i + j]) {

					if (j + 1 == a) {
						if(Arrays.equals(flower, b)) {
							minimum += 1;
							flag=false;
						}
						break;
					}
					j = j + 1;// increase j

				} else {
					flag = false;
					break;
				}

		}
		System.out.print(minimum);
	}
}