Eroare de compilare: user.c: In function ‘main’: user.c:18: error: ‘C’ undeclared (first use in this function) user.c:18: error: (Each undeclared identifier is reported only once user.c:18: error: for each function it appears in.) user.c:20: error: ‘D’ undeclared (first use in this function) user.c:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:12: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result