/in/foo.cc: In function 'bool rn(int)':
/in/foo.cc:6:21: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    6 |         if(year%4==0&&year%100!=0||year%400==0)return true;
      |            ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:24:22: error: 'monthday' was not declared in this scope; did you mean 'montnday'?
   24 |                 if(d>monthday(y,m))
      |                      ^~~~~~~~
      |                      montnday