B. Koala and Lightstime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputIt is a holiday season, and Koala is decorating his house with cool lights! He owns n lights, all of which flash periodically.After taking a quick glance at them, Koala realizes that each of his lights can be described with two parameters a_i and b_i. Light with parameters a_i and b_i will toggle (on to off, or off to on) every a_i seconds starting from the b_i-th second. In other words, it will toggle at the moments b_i, b_i + a_i, b_i + 2 \cdot a_i and so on.You know for each light whether it's initially on or off and its corresponding parameters a_i and b_i. Koala is wondering what is the maximum number of lights that will ever be on at the same time. So you need to find that out.  Here is a graphic for the first example. InputThe first line contains a single integer n (1 \le n \le 100), the number of lights.The next line contains a string s of n characters. The i-th character is "1", if the i-th lamp is initially on. Otherwise, i-th character is "0".The i-th of the following n lines contains two integers a_i and b_i (1 \le a_i, b_i \le 5)  — the parameters of the i-th light.OutputPrint a single integer — the maximum number of lights that will ever be on at the same time.ExamplesInput
3
101
3 3
3 2
3 1
Output
2
Input
4
1111
3 4
5 2
3 1
3 2
Output
4
Input
6
011100
5 3
5 5
2 4
3 5
4 2
1 5
Output
6
NoteFor first example, the lamps' states are shown in the picture above. The largest number of simultaneously on lamps is 2 (e.g. at the moment 2).In the second example, all lights are initially on. So the answer is 4.
3
101
3 3
3 2
3 1

2 
['implementation', 'math', 'number theory', '*1300']