View Compilation Error

0_0_24098446_31234.cpp: In function 'int main()':
0_0_24098446_31234.cpp:4:21: error: 'scanf' was not declared in this scope
  while(scanf("%d",&T)!=EOF)
                     ^
0_0_24098446_31234.cpp:4:24: error: 'EOF' was not declared in this scope
  while(scanf("%d",&T)!=EOF)
                        ^
0_0_24098446_31234.cpp:17:20: error: 'printf' was not declared in this scope
   printf("%d\n",ans);
                    ^