Borderou de evaluare (job #20373)

Eroare de compilare: user.c:2:1: error: unknown type name 'using' user.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std' user.c: In function 'main': user.c:4:22: warning: unused variable 'cf' [-Wunused-variable] user.c:5:12: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] user.c:6:12: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] user.c:7:10: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] user.c:9:14: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]