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++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include<iostream>
using namespace std;
int main()
{
// 整数の入力
int n,l;
int table[n+1];
int i=0;

cin >> n;

for(int i=0; i<n; i++) std::cin >> table[i];

table[n+1]=0;
int max=0,count=0;

for(i=0;i<n;++i){
    if(max<table[i])
    max=table[i];
}

while(max!=0){
    for(i=0;i<n;++i){
        if(max==table[i]){
            if(table[i]==table[i+1])table[i]--;
            else {table[i]--;count++;}
            
        
        }
    }
    //cout << max<< endl;
    max--;
}

// 出力
cout << count<< endl;
return 0;
}