View Compilation Error

0_0_36833536_6461.cpp: In function 'int main()':
0_0_36833536_6461.cpp:13:26: error: 'scanf' was not declared in this scope
 while(scanf("%d %d",&a,&b)!=EOF)//EOF为end of file表示文件结束符
                          ^
0_0_36833536_6461.cpp:13:29: error: 'EOF' was not declared in this scope
 while(scanf("%d %d",&a,&b)!=EOF)//EOF为end of file表示文件结束符
                             ^
0_0_36833536_6461.cpp:17:18: error: 'printf' was not declared in this scope
 printf("%d\n",a+b);
                  ^