beecrowd | 1007

Difference

Adapted by Neilor Tonin, URI Brazil

Timelimit: 1

Read four integer values named A, B, C and D. Calculate and print the difference of product A and B by the product of C and D (A * B - C * D).

Input

The input file contains 4 integer values.

Output

Print DIFERENCA (DIFFERENCE in Portuguese) with all the capital letters, according to the following example, with a blank space before and after the equal signal.

Input Samples Output Samples

5
6
7
8

DIFERENCA = -26

0
0
7
8

DIFERENCA = -56

5
6
-7
8

DIFERENCA = 86