import java.util.*;

public class Main{
		
		public static void main(String args[]){
	
			Scanner sc = new Scanner(System.in);
			int a = sc.nextInt();
			int b = sc.nextInt();
			int c = sc.nextInt();
			
			
			int amountLeftInBottle1 = a - b;
			int amountRemainingInBottle2 = c - amountLeftInBottle1;
			
			if(amountRemainingInBottle2 <= 0){
				
				amountRemainingInBottle2 = 0;
				
			}
			
			System.out.println(amountRemainingInBottle2);
			
		}
}
/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