B"Vasya had three strings a , b and s , which consist of lowercase English letters. The lengths of strings a and b are equal to n , the length of the string s is equal to m . Vasya decided to choose a substring of the string a , then choose a substring of the string b and concatenate them. Formally, he chooses a segment [l_1, r_1] ( 1 <= q l_1 <= q r_1 <= q n ) and a segment [l_2, r_2] ( 1 <= q l_2 <= q r_2 <= q n ), and after concatenation he obtains a string a[l_1, r_1] + b[l_2, r_2] = a_{l_1} a_{l_1 + 1} ldots a_{r_1} b_{l_2} b_{l_2 + 1} ldots b_{r_2} . Now, Vasya is interested in counting number of ways to choose those segments adhering to the following conditions: The first line contains integers n and m ( 1 <= q n <= q 500 ,000, 2 <= q m <= q 2 cdot n ) -- the length of strings a and b and the length of the string s . The next three lines contain strings a , b and s , respectively. The length of the strings a and b is n , while the length of the string s is m . All strings consist of lowercase English letters. Print one integer -- the number of ways to choose a pair of segments, which satisfy Vasya's conditions. Let's list all the pairs of segments that Vasya could choose in the first example: "...