# your code goes here
from decimal import *
import math
x = 0.7893
beginH = Decimal(1.0 )
beginB = Decimal(1.0 )
multi = 3
adder = 2
r = Decimal(0)
for i in range( 2, 5001 ) :
r = r + Decimal( ( beginH/beginB ) * Decimal( x ** i ) )
beginH = multi * beginH + adder
beginB = multi * beginB
multi +=1
adder +=1
print(r)
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCmZyb20gZGVjaW1hbCBpbXBvcnQgKgppbXBvcnQgbWF0aAoKeCA9IDAuNzg5MwoKYmVnaW5IID0gRGVjaW1hbCgxLjAgKQpiZWdpbkIgPSBEZWNpbWFsKDEuMCApCgptdWx0aSA9IDMKYWRkZXIgPSAyCgpyID0gRGVjaW1hbCgwKQpmb3IgaSBpbiByYW5nZSggMiwgNTAwMSApIDoKCXIgPSByICsgRGVjaW1hbCggKCBiZWdpbkgvYmVnaW5CICkgKiBEZWNpbWFsKCB4ICoqIGkgKSApCgkKCWJlZ2luSCA9IG11bHRpICogYmVnaW5IICsgYWRkZXIKCWJlZ2luQiA9IG11bHRpICogYmVnaW5CCgltdWx0aSArPTEKCWFkZGVyICs9MQpwcmludChyKQo=