#!/usr/bin/python

from math import *
from random import *

n = 12

a = {}
b = {}
c = {}

for i in range(1,n):
  a[i] = pow(10,random())
  b[i] = pow(10,random())
  print a[i], b[i]
  c[i] = float(raw_input())

e2 = 0.0
for i in range(1,n):
  err = (c[i] - a[i]*b[i])/c[i]
  print "%f x %f = %f (true)  vs  %f;  err %f" % (a[i],b[i],a[i]*b[i],c[i],err)
  e2 = e2 + err*err

print "rms err: %f" % sqrt(e2/n)