Even if the world is full of counterfeits, I still regard it as wonderful.

Pile up herbs and incense, and arise again from the flames and ashes of its predecessor — as is known to many, the phoenix does it like this.

The phoenix has a rather long lifespan, and reincarnates itself once every *a*! years. Here *a*! denotes the factorial of integer *a*, that is, *a*! = 1 × 2 × ... × *a*. Specifically, 0! = 1.

Koyomi doesn't care much about this, but before he gets into another mess with oddities, he is interested in the number of times the phoenix will reincarnate in a timespan of *b*! years, that is, <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/fca843bf75b022c7a28d092dbf2df55158a8a546.png" style="max-width: 100.0%;max-height: 100.0%;"/>. Note that when *b* ≥ *a* this value is always integer.

As the answer can be quite large, it would be enough for Koyomi just to know the last digit of the answer in decimal representation. And you're here to provide Koyomi with this knowledge.
The first and only line of input contains two space-separated integers *a* and *b* (0 ≤ *a* ≤ *b* ≤ 10<sup class="upper-index">18</sup>).
In the first example, the last digit of <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/99c47ca8b182f097e38094d12f0c06ce0b081b76.png" style="max-width: 100.0%;max-height: 100.0%;"/> is 2;

In the second example, the last digit of <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/9642ef11a23e7c5a3f3c2b1255c1b1b3533802a4.png" style="max-width: 100.0%;max-height: 100.0%;"/> is 0;

In the third example, the last digit of <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/844938cef52ee264c183246d2a9df05cca94dc60.png" style="max-width: 100.0%;max-height: 100.0%;"/> is 2.
2 4
2
0 10
0
107 109
2
10 13
6
998244355 998244359
4
999999999000000000 1000000000000000000
0
2 3
3
3 15
0
24 26
0
14 60
0
11 79
0
1230 1232
2
2633 2634
4
535 536
6
344319135 396746843
0
696667767 696667767
1
419530302 610096911
0
238965115 821731161
0
414626436 728903812
0
274410639 293308324
0
650636673091305697 650636673091305702
0
651240548333620923 651240548333620924
4
500000000000000000 1000000000000000000
0
999999999999999999 1000000000000000000
0
1000000000000000000 1000000000000000000
1
0 4
4
50000000062000007 50000000062000011
0
0 0
1
1 1
1
0 2
2
10000000000012 10000000000015
0
5 5
1
12 23
0
0 11
0
11111234567890 11111234567898
0
0 3
6
1 2
2
999999999999999997 999999999999999999
2
4 5
5
0 1
1
101 1002
0
0 100000000000000001
0
99999999999999997 99999999999999999
2
14 15
5
8 19
0
12 22
0
999999999999996 999999999999999
4
1 3
6
124 125
5
11 32
0
0 5
0
0 999999
0
151151151515 151151151526
0
6 107
0
5 16
0
7 16
0
6 19
0
11113111111111 13111111111111
0
1 1000
0
24 25
5
0 100000000000
0
1 22
0
999999999999999996 999999999999999999
4
a,b=map(int,input().split())
a+=1
c=1
while a<=b and c%10!=0:
    c*=a*b
    a+=1
    b-=1
print(c%10)
