#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000000
#define Inf64 1000000000000000001LL

int main(){
	long long N,K;
	cin>>N>>K;
	
	long long x = K-1;
	long long y = Inf64;
	cout<<min(x,y)<<endl;
	
	return 0;
}