View Compilation Error

0_0_23072988_31389.cpp: In function 'int main()':
0_0_23072988_31389.cpp:5:29: error: 'scanf' was not declared in this scope
     while(scanf("%d%d",&x,&n)!=EOF)
                             ^
0_0_23072988_31389.cpp:5:32: error: 'EOF' was not declared in this scope
     while(scanf("%d%d",&x,&n)!=EOF)
                                ^
0_0_23072988_31389.cpp:9:20: error: 'printf' was not declared in this scope
         printf("\n");
                    ^