/in/foo.cc: In function 'int main()':
/in/foo.cc:11:5: warning: comparison of constant '86400' with boolean expression is always true [-Wbool-compare]
 1<=s<=86400;
 ~~~~^~~~~~~
/in/foo.cc:11:2: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
 1<=s<=86400;
 ~^~~
/in/foo.cc:11:5: warning: statement has no effect [-Wunused-value]
 1<=s<=86400;
 ~~~~^~~~~~~