B'It 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. The first line contains a single integer n ( 1 <= n <= 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 <= a_i, b_i <= 5 ) -- the parameters of the i -th light. Print a single integer -- the maximum number of lights that will ever be on at the same time. For 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 . '...