import java.util.*;

public class Main
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	}
} import java.util.*; util.* java public class Main
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	}
} Main public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	} main {
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int a a b b c; c a=sc.nextInt() a sc.nextInt() sc.nextInt sc b=sc.nextInt() b sc.nextInt() sc.nextInt sc c=sc.nextInt() c sc.nextInt() sc.nextInt sc if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		} a>b+c a b+c b c {
			System.out.println("0");
		} System.out.println("0") System.out.println System.out System System.out "0" {
			System.out.println(Math.abs(b+c-a));
		} System.out.println(Math.abs(b+c-a)) System.out.println System.out System System.out Math.abs(b+c-a) Math.abs Math b+c-a b+c b c a String args[] args public class Main
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	}
} public class Main
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	}
} Main
import java.util.*;

public class Main
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int a,b,c;
		a=sc.nextInt();
		b=sc.nextInt();
		c=sc.nextInt();
		if(a>b+c)
		{
			System.out.println("0");
		}
		else
		{
			System.out.println(Math.abs(b+c-a));
		}
	}
}