View Compilation Error

0_0_33811888_31866.cpp: In function 'll determinant(int)':
0_0_33811888_31866.cpp:17:47: error: invalid operands of types 'void' and 'const ll {aka const long long int}' to binary 'operator%'
                         swap(B[i][k],B[j][k])%mod;
                                               ^