View Compilation Error

0_0_13699407_15577.cpp:51:1: error: 'll' does not name a type
 ll solve()
 ^
0_0_13699407_15577.cpp: In function 'int main()':
0_0_13699407_15577.cpp:89:17: error: 'solve' was not declared in this scope
   cout << solve() << endl;
                 ^