What is the meaning of the judge's reply?
Here is a list of the judge's replies and their meaning: 
    Wait: The judge is so busy that it can't judge your submit at the moment, usualy you just need to wait a minute and your submit will be judged.
    Accepted : OK! Your program is correct!.
    Presentation Error : Your output format is not exactly the same as the judge's output, although your answer to the problem is correct. Check your output for spaces, blank lines,etc against the problem output specification.
    Wrong Answer : Correct solution not reached for the inputs. The inputs and outputs that we use to test the programs are not public (it is recomendable to get accustomed to a true contest dynamic ;-).
    Runtime Error : Your program failed during the execution (segmentation fault, floating point exception...). The exact cause is reported to the user.
    Time Limit Exceeded : Your program tried to run during too much time.
    Memory Limit Exceeded : Your program tried to use more memory than the judge default settings.
    Output Limit Exceeded: Your program tried to write too much information. This usually occurs if it goes into a infinite loop. Currently the output limit is 1M bytes.
    Compile Error : The compiler could not compile your ANSI program. Of course, warning messages are not error messages. Click the link at the judge reply to see the actual error message.
       Other Error :Maybe a unkown error occored in  system, please contact us!

Why did I get a Compile Error? It's well done!
There are some differences between GNU and MS-VC++, such as:
    main must be declared as int, void main will end up with a Compile Error.
    i is out of definition after block "for(int i=0...){...}"
    itoa is not an ANSI function.
    __int64 of VC is not ANSI, but you can use long long for 64-bit integer.

What does Runtime Error stand for?
The possible cases of your encountering this error are:
    1.buffer overflow --- usually caused by a pointer reference out of range.
    2.stack overflow --- please keep in mind that the default stack size is 8192K.
    3.illegal file access --- file operations are forbidden on our judge system.
    4.Divided by 0
    5.Programme aborted before it should be finished.

Where is the input and the output?
    Your program shall read input from stdin('Standard Input') and write output to stdout('Standard Output').For example,you can use 'scanf' in C or 'cin' in C++ to read from stdin,and use 'printf' in C or 'cout' in C++ to write to stdout.
    User programs are not allowed to open and read from/write to files, you will get a "Runtime Error" if you try to do so.

Here is a sample solution for problem 1000 using C++:
#include <iostream>
using namespace std;

int main()
    int a,b;
    while(cin >> a >> b&&(a||b))
        cout << a+b << endl;

Here is a sample solution for problem 1000 using C:
#include <stdio.h>

int main()
    int a,b;
    while(scanf("%d %d",&a, &b)&&(a||b))

Zhe Jiang University Of Technology Online Programming Space Beta1.3
Designed & Developped By Jin Qiwei
 All Copyright Reserved 2006