#include #ifndef LOCAL_ #define fprintf if( false ) fprintf #endif // LOCAL_ #define dump() fprintf(stderr, "#%s.%d\n", __func__, __LINE__); #define dumpl(x1) fprintf(stderr, "#%s.%d (%s) = (%ld)\n", __func__, __LINE__, #x1, x1); #define dumpll(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%ld, %ld)\n", __func__, __LINE__, #x1, #x2, x1, x2); #define dumplll(x1, x2, x3) fprintf(stderr, "#%s.%d (%s, %s, %s) = (%ld, %ld, %ld)\n", __func__, __LINE__, #x1, #x2, #x3, x1, x2, x3); #define dumpd(x1) fprintf(stderr, "#%s.%d (%s) = (%lf)\n", __func__, __LINE__, #x1, x1); #define dumpdd(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%lf, %lf)\n", __func__, __LINE__, #x1, #x2, x1, x2); #define loop for(;;) typedef std::vector LI; typedef std::queue QI; #define rep(i,n) for(long i = 0; i < (long)n; ++i) const double pi = M_PI; const long mod = 1000000007; template void scan1(T& x) { fprintf(stderr, "unknown type\n"); } template<> void scan1(long& x) { if( scanf("%ld", &x) < 0 ) exit(0); } template<> void scan1(std::string& x) { if( not ( std::cin >> x ) ) exit(0); } void scan() {} template void scan(Head& x, Tail&... xs) { scan1(x); scan(xs...); } long modpow(long x, long n) { if( n == 0 ) return 1; long t = x * x % mod; return modpow(t, n / 2) * (n % 2 == 1 ? x : 1) % mod; } struct Solver { Solver() { fprintf(stderr, "--------Solver begin--------\n"); } ~Solver() { fprintf(stderr, "--------Solver end--------\n"); } struct T { T(long x, long y, long c) : x(x), y(y), c(c) {} long x, y; long c; bool operator < (const T& t) const { // if( c != t.c ) return c > t.c; // return x < t.x; return c > t.c; } }; void solve() { long n, c, v; scan(n, c, v); std::priority_queue q; LI xs(112345, (1LL << 53)); q.push(T(1, 0, 0)); while( not q.empty() ) { T t = q.top(); q.pop(); // if( xs[t.x+t.y] < t.c ) continue; // xs[t.x] = t.c; if( t.x >= n ) { printf("%ld\n", t.c); return; } if( t.x != t.y ) q.push(T(t.x, t.x, t.c+c)); q.push(T(t.x+t.y, t.y, t.c+v)); } } }; int main() { loop std::unique_ptr(new Solver())->solve(); }