#include using namespace std; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define rep1(i, n) for (int i = 1; i < (int)(n+1); i++) #define repn(i,a,b) for (int i = (int)(a) ; i < (int)(b+1); i++) #define repv(i, n) for (int i = (int)(n-1); i >= 0; i--) #define all(x) (x).begin(),(x).end() #define rall(x) (x).rbegin(),(x).rend() #define sz(x) ((int)(x).size()) #define cauto const auto& #define bit(n) (1LL<<(n)) #define uni(v) v.erase( unique(v.begin(), v.end()), v.end() ); using ll = long long; using P = pair; using PP = pair; using Graph = vector>; #ifdef LOCAL #include #define debug(...) debug::multi_print(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (static_cast(0)) #endif int main(){ ll n,a,b; cin >> n >> a >> b; ll ans =0; if(n%2== 1){ ans = (n-1)*a + b; } else { ans = (n-1)*a; } ans = max(ans,b * n-a*(n-1)); cout << -ans << endl; return 0; }