UVa 10035 Primary Arithmetic

http://acm.cs.nthu.edu.tw/problem.php?pid=7075

#include <stdio.h>

int main(int argc, const char * argv[])
{

    int n1,n2;
    while (scanf("%d%d",&n1,&n2)!=EOF && !(n1==0&&n2==0)) {
        int tmp=0;
        int carry = 0;
        while (n1||n2) {
            tmp = (n1%10)+(n2%10)+tmp;
            tmp/=10;
            if (tmp)
                carry++;
            n1/=10;
            n2/=10;
        }
        if (carry==0)
            printf("No carry operation.\n");
        else if(carry == 1)
            printf("1 carry operation.\n");
        else
            printf("%d carry operations.\n",carry);
    }
    return 0;
}