13452번 - Edsger Dijkstra 다국어

The Turing award winner Edsger Wybe Dijkstra is a dutch computer scientist who has an annoyingly confusing name that Asians have trouble pronouncing. In 1960s, He gave the following quote.

For a number of years I have been familiar with the observation that the quality of programmers is a decreasing function of the density of go to statements in the programs they produce. More recently I discovered why the use of the go to statement has such disastrous effects, and I became convinced that the go to statement should be abolished from all “higher level” programming languages.

You don’t want to produce low quality codes, do you? However, your source code contains no loop statements. The only kind of flow control statements in your source code is the if-goto. To decrease the density, you have to try and eliminate all the if-goto statements in your source code written in a C-like language and replace them with do-while loops in the following manner.

• Assume the if-goto statement looks like “if (boolean_expression) goto some_label;”.
• Insert a copy of “do {” right after where some_label is declared.
• Replace ‘if’ by ‘} while’.
• Remove ‘goto some_label’.

For example, the following code

int main() {
    int score;
    get_score:
    scanf("%d",&score);
    if (score < 0 || score > 100) goto get_score;
    if (score < 60) goto fail;
    fail:
    puts("you are failed!");
    return 0;
}

will be modified into

int main() {
int score;
    get_score: do {
    scanf("%d",&score);
    } while (score < 0 || score > 100) ;
    } while (score < 60) ;
    fail: do {
    puts("you are failed!");
    return 0;
}

It is not too surprising that the code above cannot be compiled. Here is your new task: given a sequences of statements, please determine whether all if-goto statements can be replaced by do-while loops without changing the output of your code. For simplicity, you may assume all statements are either in the following two forms.

• Form 1: “line_x: puts("x");” where x is corresponding line number of this statement and “puts("x");” prints the line number x.
• Form 2: “if (expr_x()) goto line_y;” where x is the corresponding line number of this statement and line_y is a valid label in the program. “expr_x()” will return true on first x invocations, and it will return false afterward.

Note that the output of the program should be considered as different from the original output if the modification makes the code unable to be compiled.

In the first line of input, there will be a single integer T (T ≤ 20) on a line representing the number of test cases.

Each test case is consists of a sequence of statements. Each statements will be on a single line, which starts on line 1. There can be three kinds of lines: statements in form 1, statements in form 2, and “END”. “END” will indicate the end of a test case. It can only be the last line of a test case, and it should not be considered as a part of the program. There are at most 10000 statements in a single test case (END’s are excluded).

Print “good” on a single line if replacing all if-goto statements with do-while will not change the output of the program. Otherwise print “bad”. Note: you should output “bad” if the program becomes no longer compilable.