foo.cc: In function ‘bool leap(int)’:
foo.cc:4:18: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
    4 |         if(x%4==0&&x%100!=0||x%400==0)return true;
      |            ~~~~~~^~~~~~~~~~
foo.cc: In function ‘int m1(int, int)’:
foo.cc:10:32: error: ‘x’ was not declared in this scope
   10 |         else if(m==2)d=28+leap(x);
      |                                ^