View Compilation Error

0_0_36460392_13874.cpp: In function 'void solve()':
0_0_36460392_13874.cpp:166:38: error: 'm' was not declared in this scope
  repi(i, M) for (int j = 1; i * j <= m; ++j) add(b[i * j], Mul(a[i], a[j]));
                                      ^