The sum of products of digits

Find the sum of products of all digits for k-digit numbers.

For example, for k = 2 the two-digit numbers are 10, 11, 12, ..., 98, 99. The sum of products of its digits is 1 * 0 + 1 * 1 + 1 * 2 + ... + 9 * 8 + 9 * 9 = 2025.

Input

One positive integer k (k ≤ 10).

Output

Print the sum of products of all digits for k-digit numbers.

Examples