Find the problems with this program

#include

using namespace std;

int main()

{

const int SIZE = 6;

int arr[SIZE];

for(int i = 0; i <= SIZE; i++)

{

cout << "Enter next value:";

cin >> arr[i];

}

int sum;

for(int i = 0; i <= SIZE; i++)

{

sum += arr[i];

}

cout << "The sum is " << sum << endl;

return 0;

}