View Compilation Error

0_0_38847974_22724.cpp:2:12: error: expected ',' or ';' before 'long'
    2 | #define ll long long
      |            ^~~~
0_0_38847974_22724.cpp:5:1: note: in expansion of macro 'll'
    5 | ll ksm(ll a,ll b)
      | ^~
0_0_38847974_22724.cpp: In function 'int main()':
0_0_38847974_22724.cpp:24:20: error: 'ksm' was not declared in this scope
   24 | else cout<<(2*n-1)*ksm(t,mod-2)%mod<<'\n';
      |                    ^~~