spoj#SNGLOOP1. Easiest Loop 1
Easiest Loop 1
Ileana D'Cruz is taking programming classes but she is having problem in understanding while loops. She is working on following set of instructions -
INTEGER I = 0, S, U = 1010;
WHILE (I < U) {
S = (3 * S) + (5 * I);
I = I + 1;
}
Let Sk be the value assigned to INTEGER S for the iteration I = (k + 1) and n, m, p be positive integers such that m > n. Ileana knows the values of n and m but she forgot the initial value of S. She is trying to find the unit digit of p. Any initial value of S may be used. She also knows the following equality -
(2 * n + 3) * (p - 1) + (4 / 5) * [(p * Sn) - Sm] = 2 * (m - n)
Input
First line of input is T(total no. of test cases). Each of next T lines contains two integers n and m.
Output
Print unit digit of p (p % 10) for each test case in separated lines.
Example
Input: 1 2 3 Output: 3
Constraints
T < 10001
Explanation
Let S = 2
S0 = 6
S1 = 23
S2 = 79
S3 = 252
Now solving the equation gives p = 3.