Valera has array a, consisting of n integers a0,a1,...,an-1, and function f(x), taking an integer from 0 to 2n-1 as its single argument. Value f(x) is calculated by formula , where value bit(i) equals one if the binary representation of number x contains a 1 on the i-th position, and zero otherwise.For example, if n=4 and x=11 (11=20+21+23), then f(x)=a0+a1+a3.Help Valera find the maximum of function f(x) among all x, for which an inequality holds: 0 \le x \le m.

Input The first line contains integer n (1 \le n \le 105) - the number of array elements. The next line contains n space-separated integers a0,a1,...,an-1 (0 \le ai \le 104) - elements of array a.The third line contains a sequence of digits zero and one without spaces s0s1... sn-1 - the binary representation of number m. Number m equals .

Output Print a single integer - the maximum value of function f(x) for all .

In the first test case m=20=1,f(0)=0,f(1)=a0=3.In the second sample m=20+21+23=11, the maximum value of function equals f(5)=a0+a2=17+10=27.