/in/foo.cc: In function 'int main()':
/in/foo.cc:9:9: warning: comparison of constant '86400' with boolean expression is always true [-Wbool-compare]
     1<=s<=86400;
     ~~~~^~~~~~~
/in/foo.cc:9:6: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
     1<=s<=86400;
     ~^~~
/in/foo.cc:9:9: warning: statement has no effect [-Wunused-value]
     1<=s<=86400;
     ~~~~^~~~~~~