/in/foo.cc:2:0: warning: ignoring #pragma G  [-Wunknown-pragmas]
 #pragma G++ optimize("O3")
 
/in/foo.cc: In function 'int GetInt()':
/in/foo.cc:11:22: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
     while(ch=getchar())if(ch>='0'&&ch<='9')break;
                      ^