/in/foo.cc:1:20: warning: extra tokens at end of #include directive
 #include<iostream> #include<cstring> #include<cstdlib> #include<ctime> using namespace std; int main() {     int x;     scanf("%d",&x);     srand(time(NULL));     printf("%d ",rand()%x); }
                    ^
/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status