foo.cc:10:15: error: empty character constant
   10 |      while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}
      |               ^~
foo.cc:10:24: error: empty character constant
   10 |      while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}
      |                        ^~
foo.cc:11:16: error: empty character constant
   11 |      while(ch>='' && ch<=''){x=x*+ch-'';ch=getchar();}
      |                ^~
foo.cc:11:26: error: empty character constant
   11 |      while(ch>='' && ch<=''){x=x*+ch-'';ch=getchar();}
      |                          ^~
foo.cc:11:38: error: empty character constant
   11 |      while(ch>='' && ch<=''){x=x*+ch-'';ch=getchar();}
      |                                      ^~
foo.cc: In function 'int read()':
foo.cc:9:12: error: expected primary-expression before ',' token
    9 |      int x=,f=;char ch=getchar();
      |            ^
foo.cc:10:39: error: 'f' was not declared in this scope
   10 |      while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}
      |                                       ^
foo.cc:10:42: error: expected primary-expression before ';' token
   10 |      while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}
      |                                          ^
foo.cc:12:15: error: 'f' was not declared in this scope
   12 |      return x*f;
      |               ^
foo.cc: At global scope:
foo.cc:16:3: error: storage size of 'a' isn't known
   16 |  }a[];
      |   ^
foo.cc:23:3: error: storage size of 'b' isn't known
   23 |  }b[];
      |   ^
foo.cc: In function 'void DFS(int, int, int)':
foo.cc:42:16: error: expected primary-expression before ';' token
   42 |          for(j=;j<cnt;j++){
      |                ^
foo.cc:46:16: error: expected primary-expression before ',' token
   46 |          DFS(i+,cnt+,smm+(b[cnt].x2-b[cnt].x1)*(b[cnt].y2-b[cnt].y1));
      |                ^
foo.cc:46:21: error: expected primary-expression before ',' token
   46 |          DFS(i+,cnt+,smm+(b[cnt].x2-b[cnt].x1)*(b[cnt].y2-b[cnt].y1));
      |                     ^
foo.cc: In function 'int main()':
foo.cc:53:12: error: expected primary-expression before ';' token
   53 |      for(i=;i<=n;i++){
      |            ^
foo.cc:56:13: error: expected primary-expression before ',' token
   56 |      sort(a+,a+n+,cmp);
      |             ^
foo.cc:56:18: error: expected primary-expression before ',' token
   56 |      sort(a+,a+n+,cmp);
      |                  ^
foo.cc:57:16: error: expected primary-expression before ',' token
   57 |      memset(b,-,sizeof b);
      |                ^
foo.cc:58:10: error: expected primary-expression before ',' token
   58 |      DFS(,,);
      |          ^
foo.cc:58:11: error: expected primary-expression before ',' token
   58 |      DFS(,,);
      |           ^
foo.cc:58:12: error: expected primary-expression before ')' token
   58 |      DFS(,,);
      |            ^
foo.cc:60:6: error: return-statement with no value, in function returning 'int' [-fpermissive]
   60 |      return ;
      |      ^~~~~~
foo.cc:52:12: warning: unused variable 'j' [-Wunused-variable]
   52 |      int i,j;
      |            ^

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