取兩數餘數，相加看是否>=10，如果前面有進位carry，記得要多加1
注意題目其實並不是兩個正整數，而是兩個非負整數(包含0)
以下為程式碼
#include <iostream>
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    long long a,b;
    while (cin >> a >> b)
    {
        if(a==b && b==0) break;
        int coun=0,carry=0;
        while(a!=0 || b!=0)
        {
            int ra=a%10,rb=b%10;
            a=a/10,b=b/10;
            if(ra+rb+carry>=10)
            {
                coun++;
                carry=1;
            }
            else carry=0;
        }
        if(coun==0) cout << "No carry operation.\n";
        else if (coun==1) cout << "1 carry operation.\n";
        else cout << coun << " carry operations.\n";
    }
    return 0;
}