Divisibility by 11

Divisibility by $11$ is often stated as follows: add the digits standing separately at even and at odd positions. If the difference of these sums is divisible by $11$, then the number is divisible by $11$. Calculate the product of these sums.

Input

A positive integer $n$ $(10\le n\le 2\cdot 10^9)$.

Output

Print the product of sums of digits at even and at odd positions.

Examples