please tell how this program working, (sequence)? output?

Question

#include <stdio.h>
#include<conio.h>
static int count;
  int incr( ) {return ++count;}
int main( )
{
    
int arr[ ]={1, 2, 3, 4};


    arr[count++]=incr( );
   printf("arr[count]=%d\n", arr[0]);
   printf("arr[count]=%d\n", arr[1]);
   printf("arr[count]=%d\n", arr[2]);
   printf("arr[count]=%d\n", arr[3]);
}