/in/foo.cc: In function 'int main()':
/in/foo.cc:7:6: warning: unused variable 'k' [-Wunused-variable]
  int k,a[10005],b[10005],c[10005],d[10005],n1,n2,n3;
      ^
/in/foo.cc:7:26: warning: unused variable 'c' [-Wunused-variable]
  int k,a[10005],b[10005],c[10005],d[10005],n1,n2,n3;
                          ^
/in/foo.cc:7:35: warning: unused variable 'd' [-Wunused-variable]
  int k,a[10005],b[10005],c[10005],d[10005],n1,n2,n3;
                                   ^
/in/foo.cc:7:50: warning: unused variable 'n3' [-Wunused-variable]
  int k,a[10005],b[10005],c[10005],d[10005],n1,n2,n3;
                                                  ^~