View Compilation Error

0_0_17812944_5618.cpp: In function 'int main()':
0_0_17812944_5618.cpp:12:31: error: 'scanf' was not declared in this scope
     while (~scanf("%d%d",&n,&m)) {
                               ^
0_0_17812944_5618.cpp:13:33: error: 'memset' was not declared in this scope
         memset(set,0,sizeof(set));
                                 ^
0_0_17812944_5618.cpp:23:26: error: 'printf' was not declared in this scope
         printf("%d\n",ans);
                          ^