import java.util.*;

class Main{
	public static void main(String[] $) {
		Scanner s=new Scanner(System.in);
		long a=s.nextLong(),b=s.nextLong(),c=s.nextLong();
		long r=c;
		if(a<=c)
			--r;
		if(b<=c)
			--r;
		System.out.println(r);
	}
}