View Compilation Error

0_0_34890995_8073.cpp:29:1: error: 'lom' does not name a type
 lom C(lom a,lom b) 
 ^
0_0_34890995_8073.cpp: In function 'int main()':
0_0_34890995_8073.cpp:48:19: error: 'C' was not declared in this scope
    cout<<C(m+k-1,k)<<endl;
                   ^
0_0_34890995_8073.cpp:51:22: error: 'C' was not declared in this scope
    ll ans=C(m+k-1,m-1);
                      ^