////////////////////////////// Author:eldaee, coder_viper!!!!!!!!!!!!!!!!!!!!!!!!11
#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
#define int long long
#define str string
#define vec vector
#define dou double
#define ld long double
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define YES cout << "YES" << '\n'
#define Yes cout << "Yes" << '\n'
#define NO cout << "NO" << '\n'
#define No cout << "No" << '\n'
#define gcd __gcd
#define all(x) x.begin(),x.end()
#define eldaee ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#include <bits/stdc++.h>
/*
*/
using namespace std;
void solve() {
int n, cs, cf;
cin >> n >> cs >> cf;
vec<int> v(n);
for (int i = 0; i < n; i++) {
v[i] = i + 1;
}
int res = 0;
while(true) {
if (v[0] == cs && v[n - 1] == cf) {
bool fl = true;
for (int i = 1; i < n - 1; i++) {
if ((v[i - 1] < v[i] && v[i] < v[i + 1]) || (v[i - 1] > v[i] && v[i] > v[i + 1])) {
fl = false;
break;
}
}
if (fl) {
res++;
}
}
int i = n - 2;
while(i >= 0 && v[i] >= v[i + 1]) {
i--;
}
if (i < 0) {
break;
}
int j = n - 1;
while(v[j] <= v[i]) {
j--;
}
swap(v[i], v[j]);
reverse(v.begin() + i + 1, v.end());
}
cout << res << '\n';
}
signed main()
{
eldaee
solve();
}
