Given two non-negative integers m and n, where m <= n, find the last digit of the sum Fm + Fm+1 + .... + Fn

Two non negative intergers m and n, such that m <= n.

The last digit of the sum of Fibonacci series starting from Fm to Fn.

Input:

3 7

Output:

1

Explanation:

𝐹3 + 𝐹4 + 𝐹5 + 𝐹6 + 𝐹7 = 2 + 3 + 5 + 8 + 13 = 31
Last digit of 31 = 1