View Code of Problem 101

#include<iostream>
#include<string>

using namespace std;

int main() {
	string number;
	while (cin >> number) {
		size_t pos;
		while (pos = number.find(',')) {
			if (pos == string::npos) {
				break;
			}
			else {
				number.erase(pos, 1);
			}
		}

		for (int i = 0; i < number.size();++i) {
			cout << number[i];
			if ((number.size() - i - 1) % 3 == 0 && i != number.size() - 1) {
				cout << ',';
			}
		}
		cout << endl;
	}
}