View Compilation Error

0_0_27435790_21700.cpp: In function 'int main()':
0_0_27435790_21700.cpp:4:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&n))
                     ^
0_0_27435790_21700.cpp:8:24: error: 'printf' was not declared in this scope
   printf("%d\n",a[1][1]);
                        ^