View Compilation Error

0_0_19793638_29168.cpp: In function 'int main()':
0_0_19793638_29168.cpp:25:32: error: 'a' was not declared in this scope
                         cin >> a[i];
                                ^
0_0_19793638_29168.cpp:27:22: error: 'a' was not declared in this scope
                 sort(a, a + n - 1);
                      ^
0_0_19793638_29168.cpp:29:42: error: 'm' was not declared in this scope
                 for (int i = 1; i <= n - m; i++)
                                          ^