You are given an integer written as text, possibly with a leading - sign. Format it using the standard international digit grouping: starting from the rightmost digit, insert a comma every 3 digits, and keep the sign (if any) attached directly to the first digit group with no comma between the sign and the first digit.
Input format
Line 1: a string N — an optional leading -, followed by one or more digits with no leading zero (unless the value is exactly 0).
Output format
N with comma digit-grouping applied.
Constraints
- 1 ≤ number of digits in
N≤ 30 Nmatches-?(0|[1-9][0-9]*)