View Compilation Error

0_0_37884005_18787.cpp: In function 'void s()':
0_0_37884005_18787.cpp:23:8: error: 'void s()' redeclared as different kind of symbol
 void s() {
        ^
0_0_37884005_18787.cpp:13:13: note: previous declaration 'LL s'
 LL n, k, b, s;
             ^
0_0_37884005_18787.cpp: In function 'int main()':
0_0_37884005_18787.cpp:63:14: error: expected unqualified-id before '[' token
         auto [fir, sec] = a;
              ^
0_0_37884005_18787.cpp:64:17: error: 'fir' was not declared in this scope
         cout << fir + sec << endl;
                 ^
0_0_37884005_18787.cpp:64:23: error: 'sec' was not declared in this scope
         cout << fir + sec << endl;
                       ^