View Compilation Error

0_0_18089266_5021.cpp:52:1: error: 'LL' does not name a type
 LL quickmod(LL a,LL b,LL m)
 ^
0_0_18089266_5021.cpp: In function 'int main()':
0_0_18089266_5021.cpp:89:34: error: 'quickmod' was not declared in this scope
   ll ans = quickmod(2LL, n-r, mod) - 1;
                                  ^