View Compilation Error

0_0_17474940_26486.cpp: In function 'void getmap()':
0_0_17474940_26486.cpp:30:36: error: 'scanf' was not declared in this scope
     while(m--)  {scanf("%d%d",&a,&b);add(a,b);}  
                                    ^
0_0_17474940_26486.cpp: In function 'int main()':
0_0_17474940_26486.cpp:76:29: error: 'scanf' was not declared in this scope
     while(scanf("%d%d",&n,&m)!=-1)  
                             ^
0_0_17474940_26486.cpp:98:26: error: 'printf' was not declared in this scope
         printf("%d\n",ans);  
                          ^