#include <bits/stdc++.h>

#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<long> LI;
typedef std::queue<long> QI;
#define rep(i,n) for(long i = 0; i < (long)n; ++i)
const double pi = M_PI;
const long mod = 1000000007;

template<typename T> 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<typename Head, typename... Tail>
void scan(Head& x, Tail&... xs) {
  scan1(x); scan(xs...);
}

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 {
         return c > t.c;
      }
   };
   void solve() {
      long n, c, v; scan(n, c, v);
      std::priority_queue<T> q;
      q.push(T(1, 0, 0));
      while( not q.empty() ) {
         T t = q.top(); q.pop();
         if( t.x >= n ) {
            printf("%ld\n", t.c);
            return;
         }
         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<Solver>(new Solver())->solve();
}