View Compilation Error

0_0_18925347_14939.cpp: In function 'int main()':
0_0_18925347_14939.cpp:4:30: error: 'scanf' was not declared in this scope
     while(scanf("%d %d",&a,&b)!=EOF)
                              ^
0_0_18925347_14939.cpp:4:33: error: 'EOF' was not declared in this scope
     while(scanf("%d %d",&a,&b)!=EOF)
                                 ^
0_0_18925347_14939.cpp:7:26: error: 'printf' was not declared in this scope
         printf("%d\n",a+b);
                          ^