Here integer value is not defined but how to show the output 01

Question

int n=printf("0");
Printf("%d",n);

Answer 1

Return Value of printf() in C:
If successful, the total number of characters written is returned. On failure, a negative number is returned.

Reference:
https://www.tutorialspoint.com/c_standard_library/c_function_printf.htm

Answer 2

01 is result of two printf()

In the first line

printf() prints 0, without new line

Then printf("0") returns the length 1, and store in n

The second line print n which is 1

So output is

01

Answer 3

Gordon where negative number is here? Plz explain don't understand