B'Zookeeper is buying a carton of fruit to feed his pet wabbit. The fruits are a sequence of apples and oranges, which is represented by a binary string s_1s_2 ldots s_n of length n . 1 represents an apple and 0 represents an orange. Since wabbit is allergic to eating oranges, Zookeeper would like to find the longest contiguous sequence of apples. Let f(l,r) be the longest contiguous sequence of apples in the substring s_{l}s_{l+1} ldots s_{r} . Help Zookeeper find sum_{l=1}^{n} sum_{r=l}^{n} f(l,r) , or the sum of f across all substrings. The first line contains a single integer n (1 <= q n <= q 5 cdot 10^5) . The next line contains a binary string s of length n (s_i in {0,1 }) Print a single integer: sum_{l=1}^{n} sum_{r=l}^{n} f(l,r) . In the first test, there are ten substrings. The list of them (we let [l,r] be the substring s_l s_{l+1} ldots s_r ): The lengths of the longest contiguous sequence of ones in each of these ten substrings are 0,1,2,2,1,2,2,1,1,0 respectively. Hence, the answer is 0+1+2+2+1+2+2+1+1+0 = 12 . '...