View Compilation Error

0_0_16256999_4019.cpp: In function 'int main()':
0_0_16256999_4019.cpp:8:54: error: 'eof' was not declared in this scope
  while (scanf("%d%d%d%d%d", &n, &l, &a, &b, &mod) != eof) {
                                                      ^