def check(li,c):
    ii=0
    flag=1
    smallestval=c
    for i in li:
        for j in li[ii:]:
            if i==j:
                pass
            else:
                val=int(i)+int(j)

                if smallestval!=val and val>c:
                  if (val<smallestval and smallestval!=c):
                        smallestval=val
                if smallestval==c:
                    if val>smallestval:
                          smallestval=val

        ii+=1
    f=0
    ii=0
    for i in li:
        for j in li[ii:]:
            if int(i)+int(j)==smallestval:
                f+=1

        ii+=1

    if f==1:
        return smallestval
    return c
k = 1
v1, k = raw_input("enter two numbers").split()
if int(v1)>=2 and int(v1)<=10:
    if int(k)>=1 and int(k)<=10**11:
        v2 = 2 * int(v1) + 1
        li = []
        li.append(v1)
        li.append(v2)
        li.append(int(v1) + int(v2))
        c=int(v1)+int(v2)
        while len(li) != int(k):

            copy=c
            c = check(li,c)
            if copy==c:
                c+=1
                continue
            li.append(c)
        print li[int(k)-1]