View Compilation Error

F:	emp9734405.2783Main.cc: In function 'int main()':
F:	emp9734405.2783Main.cc:13: error: 'scanf' was not declared in this scope
F:	emp9734405.2783Main.cc: In function 'bool dfs(int, int, int)':
F:	emp9734405.2783Main.cc:25: error: 'puts' was not declared in this scope
F:	emp9734405.2783Main.cc:27: error: 'puts' was not declared in this scope