/in/foo.cc: In function 'int read()':
/in/foo.cc:20:25: warning: variable 'flg' set but not used [-Wunused-but-set-variable]
  int x=0;char ch=G;bool flg=0;
                         ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:43:8: warning: unused variable 'i' [-Wunused-variable]
  int _,i,x,y,__,cnt=0;
        ^