foo.c: In function ‘main’:
foo.c:5:5: warning: implicit declaration of function ‘scanf’ [-Wimplicit-function-declaration]
    5 |     scanf("%d", &n);
      |     ^~~~~
foo.c:2:1: note: include ‘<stdio.h>’ or provide a declaration of ‘scanf’
    1 | #include <math.h>
  +++ |+#include <stdio.h>
    2 | int main() {
foo.c:5:5: warning: incompatible implicit declaration of built-in function ‘scanf’ [-Wbuiltin-declaration-mismatch]
    5 |     scanf("%d", &n);
      |     ^~~~~
foo.c:5:5: note: include ‘<stdio.h>’ or provide a declaration of ‘scanf’
foo.c:8:9: warning: implicit declaration of function ‘printf’ [-Wimplicit-function-declaration]
    8 |         printf("No\n");
      |         ^~~~~~
foo.c:8:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’
foo.c:8:9: warning: incompatible implicit declaration of built-in function ‘printf’ [-Wbuiltin-declaration-mismatch]
foo.c:8:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’
foo.c:13:9: warning: incompatible implicit declaration of built-in function ‘printf’ [-Wbuiltin-declaration-mismatch]
   13 |         printf("yes\n");
      |         ^~~~~~
foo.c:13:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’
foo.c:18:9: warning: incompatible implicit declaration of built-in function ‘printf’ [-Wbuiltin-declaration-mismatch]
   18 |         printf("No\n");
      |         ^~~~~~
foo.c:18:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’
foo.c:31:9: warning: incompatible implicit declaration of built-in function ‘printf’ [-Wbuiltin-declaration-mismatch]
   31 |         printf("yes\n");
      |         ^~~~~~
foo.c:31:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’
foo.c:33:9: warning: incompatible implicit declaration of built-in function ‘printf’ [-Wbuiltin-declaration-mismatch]
   33 |         printf("No\n");
      |         ^~~~~~
foo.c:33:9: note: include ‘<stdio.h>’ or provide a declaration of ‘printf’