Problem Statement

There are an integer sequence $A_1,...,A_N$ consisting of $N$ terms, and $N$ buttons. When the $i$-th $(1 ≦ i ≦ N)$ button is pressed, the values of the $i$ terms from the first through the $i$-th are all incremented by $1$.

There is also another integer sequence $B_1,...,B_N$. Takahashi will push the buttons some number of times so that for every $i$, $A_i$ will be a multiple of $B_i$.

Find the minimum number of times Takahashi will press the buttons.

Constraints

• All input values are integers.
• $1 ≦ N ≦ 10^5$
• $0 ≦ A_i ≦ 10^9(1 ≦ i ≦ N)$
• $1 ≦ B_i ≦ 10^9(1 ≦ i ≦ N)$

Input

The input is given from Standard Input in the following format:

N
A_1 B_1
:
A_N B_N

Output

Print an integer representing the minimum number of times Takahashi will press the buttons.