

import java.util.*;
import java.io.*;
 
public class Main {
	
		
	
	public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	}
	public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	}
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
	
		
	
	public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	}
	public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	}
} Main public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	} main {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	} InputReader obj = new InputReader(System.in); obj new InputReader(System.in) int a=obj.nextInt(); a obj.nextInt() obj.nextInt obj int b=obj.nextInt(); b obj.nextInt() obj.nextInt obj int c=obj.nextInt(); c obj.nextInt() obj.nextInt obj System.out.println(Math.max(0, c-(a-b))) System.out.println System.out System System.out Math.max(0, c-(a-b)) Math.max Math 0 c-(a-b) c (a-b) a b String args [] args public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	} InputReader public BufferedReader reader; reader public StringTokenizer tokenizer; tokenizer public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    } InputReader {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    } reader = new BufferedReader(new InputStreamReader(stream), 32768) reader new BufferedReader(new InputStreamReader(stream), 32768) tokenizer = null tokenizer null InputStream stream stream public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    } next {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    } while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        } try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            } IOException e {
	                throw new RuntimeException(e);
	            } throw new RuntimeException(e); new RuntimeException(e) {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public int nextInt() {
	        return Integer.parseInt(next());
	    } nextInt {
	        return Integer.parseInt(next());
	    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public long nextLong() {
	        return Long.parseLong(next());
	    } nextLong {
	        return Long.parseLong(next());
	    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public class Main {
	
		
	
	public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	}
	public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	}
} public class Main {
	
		
	
	public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	}
	public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	}
} Main


import java.util.*;
import java.io.*;
 
public class Main {
	
		
	
	public static void main(String args []) {
		InputReader obj = new InputReader(System.in);
		
		int a=obj.nextInt();
		int b=obj.nextInt();
		int c=obj.nextInt();
		System.out.println(Math.max(0, c-(a-b)));
	}
	public static class InputReader {
	    public BufferedReader reader;
	    public StringTokenizer tokenizer;
 
	    public InputReader(InputStream stream) {
	        reader = new BufferedReader(new InputStreamReader(stream), 32768);
	        tokenizer = null;
	    }
 
	    public String next() {
	        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
	            try {
	                tokenizer = new StringTokenizer(reader.readLine());
	            } catch (IOException e) {
	                throw new RuntimeException(e);
	            }
	        }
	        return tokenizer.nextToken();
	    }
 
	    public int nextInt() {
	        return Integer.parseInt(next());
	    }
 
	    public long nextLong() {
	        return Long.parseLong(next());
	    }
	    
 
	}
}