ACM STEP 1.1.6 A+B for Input-Output Practice (VI)

#include <iostream>using namespace std;int main(int argc, const char * argv[]){    int a,sum,n;    while((cin >>n)&&n!=0)    {        sum=0;    while(n--)    {        cin >>a;        sum+=a;            }        cout <<sum<<endl;    }    return 0;}