View Compilation Error

0_0_37753607_31985.cpp: In function 'long long int work(long long int)':
0_0_37753607_31985.cpp:30:7: error: expected unqualified-id before '[' token
  auto [x, y] = a[mid].second;
       ^
0_0_37753607_31985.cpp: In function 'void work()':
0_0_37753607_31985.cpp:52:8: error: expected unqualified-id before '[' token
   auto [x, y] = a[i].second;
        ^
0_0_37753607_31985.cpp:53:34: error: 'x' was not declared in this scope
   maxn11[i] = max(maxn11[i + 1], x + y);
                                  ^
0_0_37753607_31985.cpp:53:38: error: 'y' was not declared in this scope
   maxn11[i] = max(maxn11[i + 1], x + y);
                                      ^