Binary search program returning undesired values

I wrote a program for binary search but it is not working properly. I also wrote code to sort the array, which is working, but when I accept the element to be searched, the program stops working and returns undesired values. It is showing Process returned -1073741819 (0xC0000005) each time I run the program. Here's my code

#include <iostream>
using namespace std;

int main() {
  int arr[10], n, i, j, temp;

  cout << "Enter number of elements: ";
  cin >> n;

  for (i = 0; i < n; i++) {
    cout << "Enter element " << i + 1 << ": ";
    cin >> arr[i];
  }

  cout << "\nThe sorted array is: \n";

  for (i = 0; i < n; i++) {
    for (j = 0; j < n - i - 1; j++) {
      if (arr[j] > arr[j + 1]) {
        temp = arr[j];
        arr[j] = arr[j + 1];
        arr[j + 1] = temp;
      }
    }
  }

  for (i = 0; i < n; i++) {
    cout << arr[i] << " ";
  }

  int last, beg, mid, se, flag = 0;

  cout << "\n.\nEnter the element to be searched: ";
  cin >> se;

  last = n - 1;
  beg = 0;

  while (beg <= last) {
    mid = (last + mid) / 2;

    if (se > arr[mid])
      beg = mid + 1;

    else if (se < arr[mid])
      last = mid - 1;

    else {
      cout << se << " found at position " << mid + 1;
      flag = 1;
      break;
    }
  }

  if (flag == 0) cout << "No such thing exists...";

  return 0;
}

The bug seems to be in the following line:

mid = (last + mid)/2; 

You want mid to be assigned the value that is equidistant to both last and beg. Resolve this bug in your code and it should work.