ll sum=0,n;//n<=1e7
	for(int i=n-1;i>=1;i--)
    {
        if(sum%i==0){
            ll tmp=sum+sum/i+1;
            for(register int j=i-1;j>=1;--j)
                tmp+=tmp/j+(tmp%j!=0);
            if(tmp<=k)sum+=sum/i+1;
            else sum+=sum/i;
        }else
            sum+=sum/i+1;
    }