Problem:
Score : 100 points

Problem Statement

We have two bottles for holding water.

Bottle 1 can hold up to A milliliters of water, and now it contains B milliliters of water.

Bottle 2 contains C milliliters of water.

We will transfer water from Bottle 2 to Bottle 1 as much as possible.

How much amount of water will remain in Bottle 2?

Constraints

All values in input are integers.

1 \leq B \leq A \leq 20

1 \leq C \leq 20

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the integer representing the amount of water, in milliliters, that will remain in Bottle 2.

Sample Input 1

6 4 3

Sample Output 1

1

We will transfer two milliliters of water from Bottle 2 to Bottle 1, and one milliliter of water will remain in Bottle 2.

Sample Input 2

8 3 9

Sample Output 2

4

Sample Input 3

12 3 7

Sample Output 3

0

Solution in Fortran (gfortran v4.8.4) (judge verdict: Accepted)

module ABC136

  ! <module>s to import
  use, intrinsic :: iso_fortran_env

  ! require all variables to be explicitly declared
  implicit none

  ! accessibility of <subroutine>s and <function>s in this <module>
  public :: task_A
  
  contains
  
  subroutine task_A (volume_Container1_max, volume_Container1_contained, volume_Container2_contained)

    ! arguments for this <subroutine>
    integer(INT8), intent(in) :: volume_Container1_max
    integer(INT8), intent(in) :: volume_Container1_contained
    integer(INT8), intent(in) :: volume_Container2_contained

    ! variables for this <subroutine>
    integer(INT8) :: volume_Container1_receivable
    integer(INT8) :: volume_remained

    volume_Container1_receivable = volume_Container1_max - volume_Container1_contained

    if (volume_Container1_receivable .ge. volume_Container2_contained) then
      volume_remained = 0_INT8
    else
      volume_remained = volume_Container2_contained - volume_Container1_receivable
    end if

    write(unit=OUTPUT_UNIT, fmt='(I0)', advance='yes') volume_remained
    
    ! STEP.END
    return

  end subroutine task_A

end module ABC136

program main

  ! <module>s to import
  use,     intrinsic :: iso_fortran_env
  use, non_intrinsic :: ABC136

  ! variables for this <program>
  integer(INT8) :: A
  integer(INT8) :: B
  integer(INT8) :: C

  read(unit=INPUT_UNIT, fmt=*) A, B, C
  
  call task_A (A, B, C)

end program main