ARRAYS-MAX VALUE IN ARRAY hackerblocks

Take as input N, the size of array. Take N more inputs and store that in an array. Write a function which returns the maximum value in the array. Print the value returned.

1.It reads a number N.

2.Take Another N numbers as input and store them in an Array.

3.calculate the max value in the array and return that value.
IN MY SOLUTION ONE TEST CASE IS NOT PASSING
#include <bits/stdc++.h>
using namespace std;
int main() {
long long int n;
cin>>n;

  long long  int a[1000];
    long long int max=0;
    
    for(int i=0;i<n;i++){
        cin>>a[i];
    }

    for(int i=0;i<n;i++){
        if(a[i]>max){
         max =a[i];
        }
        
    }
    cout<<max;

}

try assigning max =a[0];