View Compilation Error

0_0_30254350_1737.cpp:1:9: error: #include expects "FILENAME" or <FILENAME>
 #include
         ^
0_0_30254350_1737.cpp: In function 'int main()':
0_0_30254350_1737.cpp:6:24: error: 'scanf' was not declared in this scope
  while(scanf("%d", &len), len)
                        ^
0_0_30254350_1737.cpp:20:17: error: 'printf' was not declared in this scope
    printf("-1\n");
                 ^
0_0_30254350_1737.cpp:34:27: error: 'printf' was not declared in this scope
    printf("1\n%d\n", index);
                           ^
0_0_30254350_1737.cpp:56:38: error: 'printf' was not declared in this scope
   printf("2\n%d %d\n", index1, index2);
                                      ^