#include <bits/stdc++.h>

const long long INF = 1e9;
// const long long MOD = 1e9 + 7;
const long long MOD = 998244353;
const long long LINF = 1e18;
using namespace std;

#define YES(n) cout << ((n) ? "YES" : "NO") << endl
#define Yes(n) cout << ((n) ? "Yes" : "No") << endl
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE" : "IMPOSSIBLE") << endl
#define Possible(n) cout << ((n) ? "Possible" : "Impossible") << endl
#define dump(x) cout << #x << " = " << (x) << endl
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define COUT(x) cout << (x) << endl
#define SCOUT(x) cout << (x) << " "
#define VECCOUT(x)                              \
  for (auto &youso_ : (x))                      \
    cout << right << setw(10) << youso_ << " "; \
  cout << endl
#define ENDL cout << endl
#define CIN(...)   \
  int __VA_ARGS__; \
  CINT(__VA_ARGS__)
#define LCIN(...)        \
  long long __VA_ARGS__; \
  CINT(__VA_ARGS__)
#define SCIN(...)     \
  string __VA_ARGS__; \
  CINT(__VA_ARGS__)
#define VECCIN(x)          \
  for (auto &youso_ : (x)) \
  cin >> youso_
#define mp make_pair
#define PQ priority_queue<long long>
#define PQG priority_queue<long long, V, greater<long long>>

typedef long long ll;
typedef vector<long long> vl;
typedef vector<long long> vi;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<vl> vvl;
typedef vector<vi> vvi;
typedef vector<vb> vvb;
typedef vector<vc> vvc;
typedef pair<long long, long long> pll;

#define COUT(x) cout << (x) << endl
void CINT()
{
}
template <class Head, class... Tail>
void CINT(Head &&head, Tail &&...tail)
{
  cin >> head;
  CINT(move(tail)...);
}
template <class T>
void mod(T &x)
{
  x %= MOD;
  x += MOD;
  x %= MOD;
}

ll GCD(ll a, ll b)
{
  if (b == 0)
    return a;
  else
    return GCD(b, a % b);
}

struct COMB
{
  vl fact, fact_inv, inv;
  void init_nCk(long long SIZE)
  {
    fact.resize(SIZE + 5);
    fact_inv.resize(SIZE + 5);
    inv.resize(SIZE + 5);
    fact.at(0) = fact.at(1) = fact_inv.at(0) = fact_inv.at(1) = inv.at(1) = 1;
    for (long long i = 2; i < SIZE + 5; i++)
    {
      fact.at(i) = fact.at(i - 1) * i % MOD;
      inv.at(i) = MOD - inv.at(MOD % i) * (MOD / i) % MOD;
      fact_inv.at(i) = fact_inv.at(i - 1) * inv.at(i) % MOD;
    }
  }
  long long nCk(long long n, long long k)
  {
    assert(!(n < k));
    assert(!(n < 0 || k < 0));
    return fact.at(n) * (fact_inv.at(k) * fact_inv.at(n - k) % MOD) % MOD;
  }
};
ll extGCD(ll a, ll b, ll &x, ll &y)
{
  if (b == 0)
  {
    x = 1;
    y = 0;
    return a;
  }
  ll d = extGCD(b, a % b, y, x);
  y -= a / b * x;
  return d;
}

void Main()
{
  LCIN(N, A, B);
  cout << min(-A * (N - 1) - N % 2 * B, A * (N - 1) - B * N) << endl;
}

int main()
{
  cout << fixed << setprecision(15);
  Main();
  return 0;
}