View Compilation Error

0_0_29209902_31068.cpp: In function 'int main()':
0_0_29209902_31068.cpp:33:26: error: 'scanf' was not declared in this scope
  while(scanf("%d%d",&n,&m)){
                          ^
0_0_29209902_31068.cpp:43:38: error: 'printf' was not declared in this scope
   printf("Case %d: %d\n",++Case,bfs());
                                      ^