Main.cc: In function 'int main()': Main.cc:7:12: error: unable to find string literal operator 'operator""c' with 'const char [9]', 'long unsigned int' arguments printf("%d-%d-%d"c,a,b); ^ Main.cc:6:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d-%d-%d",&a,&b,&c); ^