ACM 10035 -- Primary Arithmetic

#include <iostream>

using namespace std;


int main(int argc, char* argv[]){
    unsigned long long n1;
    unsigned long long n2;
    int carry = 0;
    int sum = 0;
    int count = 0;

    while(cin >> n1 >> n2) {
        if(n1 == 0 & n2 == 0)
            break;

        carry = 0;
        count = 0;
        sum = 0;

        while ((n1 > 0) || (n2 > 0)) {

            sum = carry + (n1 % 10) + (n2 % 10);

            if (sum >= 10) {
                count++;
            }

            carry = sum / 10;

            n1 /= 10;
            n2 /= 10;
        }

        if (count == 0) {
            cout << "No carry operation." << endl;
        } else if (count == 1) {
            cout << "1 carry operation." << endl;
        } else {
            cout << count << " carry operations." << endl;
        }
    }
 return 0;
}