Question

can someone help in this question
A company has a security system comprising four electronic devices
(A, B, C and D) which operate independently. Each device has a
probability of 0.1 of failure. The four electronic devices are
arranged so that the whole system operates if at least one of A or B
functions and at least one of C or D functions.
Show that the probability that the whole system functions properly
is 0.9801.
we have use probability tree need help test tomorrow please