Competitions

# PP1 Week 2 Conditionals Part 2

# Square

Four positive integers **a**, **b**, **c**, **d** are given. Find the square of any given number if there exists a square with side lengths **a**, **b**, **c**, **d** and **No** otherwise.

#### Input

Four positive integers **a**, **b**, **c**, **d**, each no more than `10`

.^{9}

#### Output

If the square exists, print the square of any input number. Otherwise print **No**.

Input example #1

7 7 7 7

Output example #1

49

Input example #2

9 6 9 6

Output example #2

No