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.
import os
line_number = 1
current_working_dir = os.getcwd()
my_local_machine = current_working_dir.find('rachel')
# print(my_local_machine)

def myinput():
    global line_number, lines, my_local_machine
    if line_number == 1:
        lines = lines.split('\n')

    # print(len(lines))
    if my_local_machine > 0:
        line = lines[line_number]
    else:
        line = input()
    
    line_number += 1
    return(line)

lines = '''
bearbtear
'''

s = myinput() 
l = len(s) 
left = 0 
right = 0 
c = 0
prev = 0  

for i in range(l-3): 
    if s[i:i+4] == 'bear': 
        left = i - prev + 1 
        right = l - (i+4) + 1
        prev = i + 1 
        c += left * right
print(c)