#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main()
{
    int n, k; cin>>n>>k;
    vector<int> a(1, k);
    for(int i=1; i<=n; ++i)
        if (i!=k) a.push_back(i);

    int res=0;
    for(int k=1; k<n; ++k) {
        int i=2;
        do {
            int cnt=0;
            for(int j=1; j<n; ++j) cnt+=a[j-1]>a[j];
            if (cnt==1) ++res;
            if (n>2) rotate(begin(a)+2, begin(a)+3, end(a));
        } while (++i<n);
        rotate(begin(a)+1, begin(a)+2, end(a));
    }
    cout<<res<<endl;
}