/in/foo.cc: In function 'int main()':
/in/foo.cc:15:18: warning: format '%d' expects a matching 'int*' argument [-Wformat=]
     scanf("%d,&x");
                  ^
/in/foo.cc:16:23: warning: 'x' is used uninitialized in this function [-Wuninitialized]
     for(int x1=3;x1<=x/2;x1=x1+2)
                      ~^~