View Compilation Error

0_0_33936415_3688.cpp: In function 'int mian()':
0_0_33936415_3688.cpp:4:29: error: 'scanf' was not declared in this scope
     while(scanf("%a%b",&a,&b)!=EOF)
                             ^
0_0_33936415_3688.cpp:4:32: error: 'EOF' was not declared in this scope
     while(scanf("%a%b",&a,&b)!=EOF)
                                ^
0_0_33936415_3688.cpp:5:23: error: 'printf' was not declared in this scope
     {  printf("%d",a+b);}
                       ^