Write a Program to perform in c Binary search for a given value in a sorted list

/* Write a Program to perform in c Binary search for a given value in a sorted list*/

#include <stdio.h>
int main()
{
  int i, first, last, middle, n, item, la[100];

  printf("Enter number of elements\n");
  scanf("%d", &n);

  printf("Enter %d integers\n", n);

  for (i = 1; i <= n; i++)
    scanf("%d", &la[i]);

  printf("Enter value to find\n");
  scanf("%d", &item);

  first = 1;
  last = n;
  middle = (first+last)/2;

  while (first <= last) {

    if(la[middle] == item)
    {
        printf("found ");
        break;
    }
      else if (item>la[middle])
    {
      first = middle + 1;
    }
    else
    {
      last = middle - 1;
    }
    middle = (first + last)/2;
  }

  if (first > last)
    printf("Not found");

  return 0;
}