/in/foo.cc: In function 'void read(_T&)':
/in/foo.cc:12:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(_t=='-') _flag=true,_t=getchar(); _x=_t-'0';
  ^~
/in/foo.cc:12:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(_t=='-') _flag=true,_t=getchar(); _x=_t-'0';
                                       ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:69:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int mid=l+r>>1;
           ~^~
/in/foo.cc:74:13: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  else printf("%d\n",ans);
       ~~~~~~^~~~~~~~~~~~