View Compilation Error

0_0_17947863_30486.cpp:22:8: error: 'N' was not declared in this scope
 LL fac[N];
        ^
0_0_17947863_30486.cpp: In function 'long long int Get_Fact(long long int)':
0_0_17947863_30486.cpp:24:5: error: 'fac' was not declared in this scope
     fac[0]=1;
     ^
0_0_17947863_30486.cpp: In function 'long long int Lucas(long long int, long long int, long long int)':
0_0_17947863_30486.cpp:33:18: error: 'fac' was not declared in this scope
         ret=(ret*fac[a]*PowMod(fac[b]*fac[a-b]%p,p-2,p))%p;
                  ^