View Compilation Error

0_0_33560492_7918.cpp:22:1: error: 'LL' does not name a type
 LL solve(int n)
 ^
0_0_33560492_7918.cpp: In function 'int main()':
0_0_33560492_7918.cpp:73:26: error: 'solve' was not declared in this scope
   printf("%lld\n",solve(n));
                          ^