#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#define int long long
#define ul unsigned long long
#define db double
#define fo(i,l,r) for(int i=l;i<=r;i++)
#define rf(i,r,l) for(int i=r;i>=l;i--)
using namespace std;
int n,p,q,ans;const int inf=1e18;
void swap(int &x,int &y){int t=x;x=y;y=t;}
int max(int x,int y){return x>y?x:y;}
int min(int x,int y){return x<y?x:y;}
int gs(int n,int x){if(!x)return inf;int y=(n+1)/(x+1);return p*x*x*y+q*(n-x*y);}
int read(){
	int sum=0;bool f=0;char c=getchar();
	for(;c<48||c>57;c=getchar())if(c==45)f=1;
	for(;c>=48&&c<=57;c=getchar())sum=sum*10+(c&15);
	return f?-sum:sum;
}
signed main(){
	freopen("money.in","r",stdin);freopen("money.out","w",stdout);
	n=read();p=read();q=read();ans=n*q;
	fo(i,1,n)
	{
		if(p*i>=q)break;
		ans=min(ans,gs(n,i));
		for(int j=1;(i+1)*j<=n;j++)
			ans=min(ans,p*i*i*j+q*j+gs(n-(i+1)*j,i-1));
	}
	printf("%lld",ans);
	return 0;
}