The bear has a string *s* = *s*<sub class="lower-index">1</sub>*s*<sub class="lower-index">2</sub>... *s*<sub class="lower-index">|*s*|</sub> (record |*s*| is the string's length), consisting of lowercase English letters. The bear wants to count the number of such pairs of indices *i*, *j* (1 ≤ *i* ≤ *j* ≤ |*s*|), that string *x*(*i*, *j*) = *s*<sub class="lower-index">*i*</sub>*s*<sub class="lower-index">*i* + 1</sub>... *s*<sub class="lower-index">*j*</sub> contains at least one string "bear" as a substring.

String *x*(*i*, *j*) contains string "bear", if there is such index *k* (*i* ≤ *k* ≤ *j* - 3), that *s*<sub class="lower-index">*k*</sub> = *b*, *s*<sub class="lower-index">*k* + 1</sub> = *e*, *s*<sub class="lower-index">*k* + 2</sub> = *a*, *s*<sub class="lower-index">*k* + 3</sub> = *r*.

Help the bear cope with the given problem.
The first line contains a non-empty string *s* (1 ≤ |*s*| ≤ 5000). It is guaranteed that the string only consists of lowercase English letters.
def solve():
    s = input()
    count = 0
    n = len(s)
    for i in range(n - 3):
        isBear = False
        for j in range(i + 3, n):
            if isBear or s[j - 3:j + 1] == "bear":
                isBear = True
                count += 1
    print(count)

if __name__ == "__main__":
    # Uncomment the following lines if you want to redirect standard input/output to files.
    # import sys
    # sys.stdin = open("../I&O/Input.txt", "r")
    # sys.stdout = open("../I&O/Output.txt", "w")
    # sys.stderr = open("../I&O/Error.txt", "w")

    solve()
