View Compilation Error

0_0_21508243_2125.cpp: In function 'void cdq(int, int)':
0_0_21508243_2125.cpp:83:56: error: too few arguments to function 'LL mul(LL, LL)'
     for(int i = 0; i < len; ++i) s[i] = mul(y[i] * s[i]);
                                                        ^
0_0_21508243_2125.cpp:17:4: note: declared here
 LL mul(LL x,LL y){
    ^