Reading a single character in C

scanf("%c",&in);

leaves a newline which is consumed in the next iteration.

Change it to:

scanf(" %c",&in); // Notice the whitespace in the format string

which tells scanf to ignore whitespaces.

OR

scanf(" %c",&in);
getchar(); // To consume the newline 

To read just one char, use getchar instead:

int c = getchar();
if (c != EOF)
  printf("%c\n", c);

in scanf("%c",&in); you could add a newline character \n after %c in order to absorb the extra characters

scanf("%c\n",&in);