#include<bits/stdc++.h>
using namespace std;
#define N 1005
#define int long long
int n,m,i,j,ans=1e18,c,u[N],s[N],h,lts[N];
signed main(){
	scanf("%lld%lld",&n,&c);
	for(i=1;i<=n;i++){
		int k=n/i,p=0,sum=0,g=0;//12/8
		k=max(k,2ll),h=1;
		memset(u,0,sizeof(u));
		for(j=k/2+1;j<=n;j+=k) u[j]=1,p++;
		j=1,m=0;
		while(p<i){
			if(u[j]==0) u[j]=1,p++;
			j++;
		}
		for(j=1;j<=n;j++){
			if(u[j]==1) s[++m]=j;
		}
		s[0]=-1e18,s[m+1]=1e18;
		for(j=1;j<=m;j++){
			sum+=(j-1)*s[j]-g;
			g+=s[j];
		}
		for(j=1;j<=n;j++){
			if(j>s[h]) h++;
			if(j-s[h-1]<s[h]-j) lts[j]=s[h-1];
			else lts[j]=s[h];
		}
		sum+=i*c; 
		for(j=1;j<=n;j++) sum+=abs(lts[j]-j);
		ans=min(ans,sum);
//		for(j=1;j<=n;j++) printf("%lld ",lts[j]);
//		printf("%lld\n",sum);
//		2 4 7
	}
	printf("%lld\n",ans);
	return 0;
}