View Compilation Error

0_0_34094848_17597.cpp: In function 'mat mul(mat, mat)':
0_0_34094848_17597.cpp:25:61: error: expected ')' before ';' token
     res.a[i][j] = (res.a[i][j] + a.a[i][k] * b.a[k][j] % mod;
                                                             ^