/in/foo.cc: In function 'int main()':
/in/foo.cc:6:10: warning: comparison of constant '0' with boolean expression is always true [-Wbool-compare]
  86399>=t>=0;
  ~~~~~~~~^~~
/in/foo.cc:6:7: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
  86399>=t>=0;
  ~~~~~^~~
/in/foo.cc:6:10: warning: statement has no effect [-Wunused-value]
  86399>=t>=0;
  ~~~~~~~~^~~