import java.util.*;
public class Main {
public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
  	int numA = sc.nextInt();
  	int numB = sc.nextInt();
  	int numC = sc.nextInt();
  	
  	int ans = numC - (numA - numB);
  	if(ans < 0) ans = 0;
  
  	System.out.println(ans);
  
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz