What will be the output of the following C code? (Assuming that we have entered the value 1 in the standard input)

#include <stdio.h>
void main()
{
    int ch;
    printf("enter a value between 1 to 2:");
    scanf("%d", &ch);
    switch (ch, ch + 1)
    {
       case 1:
          printf("1\n");
          break;
       case 2:
          printf("2");
          break;
    }
}