/in/foo.cc: In function 'int main()':
/in/foo.cc:7:16: warning: comparison of constant '10' with boolean expression is always true [-Wbool-compare]
    7 |         if(1<=P<=10)
      |            ~~~~^~~~
/in/foo.cc:7:13: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
    7 |         if(1<=P<=10)
      |            ~^~~
/in/foo.cc:9:16: warning: comparison of constant '20' with boolean expression is always true [-Wbool-compare]
    9 |         if(10<P<=20)
      |            ~~~~^~~~
/in/foo.cc:9:14: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
    9 |         if(10<P<=20)
      |            ~~^~
/in/foo.cc:11:18: warning: comparison of constant '20' with boolean expression is always false [-Wbool-compare]
   11 |         if(100>=P>20)
      |            ~~~~~~^~~
/in/foo.cc:11:15: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
   11 |         if(100>=P>20)
      |            ~~~^~~