Two little greedy bears have found two pieces of cheese in the forest of weight *a* and *b* grams, correspondingly. The bears are so greedy that they are ready to fight for the larger piece. That's where the fox comes in and starts the dialog: "Little bears, wait a little, I want to make your pieces equal" "Come off it fox, how are you going to do that?", the curious bears asked. "It's easy", said the fox. "If the mass of a certain piece is divisible by two, then I can eat exactly a half of the piece. If the mass of a certain piece is divisible by three, then I can eat exactly two-thirds, and if the mass is divisible by five, then I can eat four-fifths. I'll eat a little here and there and make the pieces equal". 

The little bears realize that the fox's proposal contains a catch. But at the same time they realize that they can not make the two pieces equal themselves. So they agreed to her proposal, but on one condition: the fox should make the pieces equal as quickly as possible. Find the minimum number of operations the fox needs to make pieces equal.
The first line contains two space-separated integers *a* and *b* (1 ≤ *a*, *b* ≤ 10<sup class="upper-index">9</sup>).
a,b=list(map(int,input().split()))
if(a==b):
    print(0)
else:
    d1={2:0,3:0,5:0}
    d2={2:0,3:0,5:0}
    f1=0
    f2=0
    while(a>1):
        if(a%2==0):
            a=a//2
            d1[2]+=1
        elif(a%3==0):
            a=a//3
            d1[3]+=1
        elif(a%5==0):
            a=a//5
            d1[5]+=1
        else:
            f1=1
            break
    while(b>1):
        if(b%2==0):
            b=b//2
            d2[2]+=1
        elif(b%3==0):
            b=b//3
            d2[3]+=1
        elif(b%5==0):
            b=b//5
            d2[5]+=1
        else:
            f2=1
            break
    if(a!=b):
        print(-1)
    else:
        t1=0
        if(d1[2]!=d2[2]):
            t1+=abs(d1[2]-d2[2])
        if(d1[3]!=d2[3]):
            t1+=abs(d2[3]-d1[3])
        if(d1[5]!=d2[5]):
            t1+=abs(d2[5]-d1[5])
        print(t1)
    
        
