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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main(void) {
	int N;
	scanf("%d" ,&N);
	int s[N];
	int count=0,max=0;
	for(int i=0;i<N;i++)
	{
		scanf("%d", &s[i]);
		if(max<s[i])
		{
			max=s[i];
		}
	}
	int t = s[0];
	for(int i=0;i<max;i++)
	{
		for(int j=0;j<N;j++)
		{
			
			if(((s[j]==0)&&(j!=0)&&(t!=0))||((j==N-1)&&(s[j]>0)&&(s[j-1]>0)))
			{
				count=count+1;
			}
			t =s[j];
			
			if(s[j]>0)
			{
				s[j]=s[j]-1;
				
			} 
		}
	}
	printf("%d", count);
}