View Compilation Error

0_0_27928467_7538.cpp: In function 'll C(ll, ll, ll)':
0_0_27928467_7538.cpp:45:46: error: too few arguments to function 'll inv(ll, ll)'
     return  fac[n]*inv(mul(fac[m],fac[n-m],p))%p;
                                              ^
0_0_27928467_7538.cpp:38:4: note: declared here
 ll inv(ll a,ll p)//逆元
    ^