/in/foo.c: In function 'main':
/in/foo.c:5:21: error: 'score' undeclared (first use in this function)
    5 |         scanf("%d",&score);
      |                     ^~~~~
/in/foo.c:5:21: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:7:31: error: 'A' undeclared (first use in this function)
    7 |                 printf("%d\n",A);
      |                               ^
/in/foo.c:9:31: error: 'B' undeclared (first use in this function)
    9 |                 printf("%d\n",B);
      |                               ^
/in/foo.c:11:31: error: 'C' undeclared (first use in this function)
   11 |                 printf("%d\n",C);
      |                               ^
/in/foo.c:13:31: error: 'D' undeclared (first use in this function)
   13 |                 printf("%d\n",D);
      |                               ^
/in/foo.c:4:13: warning: unused variable 'n' [-Wunused-variable]
    4 |         int n;
      |             ^