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 sys
input = sys.stdin.readline

############ ---- Input Functions ---- ############
def inp(): # int
    return(int(input()))
def inlt(): # list
    return(list(map(int,input().split())))
def insr(): # string as char list
    s = input()
    return(list(s[:len(s) - 1]))
def instr(): # string
    return input()
def invr(): # spaced ints
    return(map(int,input().split()))

s = instr()
start_idx = []
#
for i in range(len(s) - 3):
    if s[i:i+4] == 'bear':
        start_idx.append(i)

if not start_idx:
    print(0)
else:
    ans = 0
    curr_idx = 0 # first idx in start_idx such that st[curr] >= j
    l = len(s)
    for j in range(len(s) - 3): # starting idx for substr of j
        ans += l - (start_idx[curr_idx] + 4)
        if j == start_idx[curr_idx]:
            curr_idx += 1
        if curr_idx == len(start_idx):
            break
    print(ans)


