View Compilation Error

0_0_39035283_11789.c: In function 'main':
0_0_39035283_11789.c:13:28: error: 'p' undeclared (first use in this function)
   13 |                         if(p[a]==0) p[a]=a;
      |                            ^
0_0_39035283_11789.c:13:28: note: each undeclared identifier is reported only once for each function it appears in
0_0_39035283_11789.c:19:34: error: 'N' undeclared (first use in this function)
   19 |                 for(i=1,sum=0;i<=N;i++)
      |                                  ^