Main.c: In function ‘main’:
Main.c:7:9: error: ‘i’ undeclared (first use in this function)
    7 |     for(i=1;i<=b;i++)
      |         ^
Main.c:7:9: note: each undeclared identifier is reported only once for each function it appears in
Main.c:4:11: warning: unused variable ‘z’ [-Wunused-variable]
    4 |     int b,z;
      |           ^