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"

long long int my_f(long long int N){
  if (N%2==0) {
    return N/2;
  }
  return 3*N+1;
}

int main(int argc, char const *argv[]) {
  long long int S;
  int c_f=0;
  int c_t=0;
  scanf("%lld", &S);
  int i=1;
  while (S!=1) {
    S=my_f(S);
    if (S==2) {c_t=1;}
    if (S==4) {c_f=1;}
    i++;
  }
  if (c_f==1) {
    i=i+1;
  }else if(c_t==1){
    i=i+2;
  }else{
    i=i+3;
  }
  printf("%d", i);
  return 0;
}