View Compilation Error

0_0_14226483_4300.cpp:3:1: error: expected initializer before 'LL'
 LL gcd(LL x,LL y)
 ^
0_0_14226483_4300.cpp:10:1: error: 'LL' does not name a type
 LL lcm(LL x,LL y)
 ^
0_0_14226483_4300.cpp: In function 'int main()':
0_0_14226483_4300.cpp:20:9: error: 'LL' was not declared in this scope
         LL n,ans=0;
         ^
0_0_14226483_4300.cpp:21:23: error: 'n' was not declared in this scope
         scanf("%lld",&n);
                       ^
0_0_14226483_4300.cpp:23:13: error: 'ans' was not declared in this scope
             ans=max(ans,lcm(n/2-i,n-n/2+i));
             ^
0_0_14226483_4300.cpp:23:42: error: 'lcm' was not declared in this scope
             ans=max(ans,lcm(n/2-i,n-n/2+i));
                                          ^
0_0_14226483_4300.cpp:23:43: error: 'max' was not declared in this scope
             ans=max(ans,lcm(n/2-i,n-n/2+i));
                                           ^
0_0_14226483_4300.cpp:24:24: error: 'ans' was not declared in this scope
         printf("lld\n",ans);
                        ^