Competitions

# Week 1 Introduction Part 1

# School concert

At the school concert a students sang, b students danced, and c students sang and danced. How many participants were there in total?

## Input data

Three positive integers a, b and c~(a, b, c \le 10^{18}).

## Output data

Print the number of participants at the school concert.

## Examples

Input example #1

13 9 5

Output example #1

17