/in/foo.cc: In function 'void ntt(int*, int*, int*)':
/in/foo.cc:64:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for (int i = 0; i <= l; ++i) C[i] = 1ll * A[i] * B[i] % P; dft(C, -1, l);
  ^~~
/in/foo.cc:64:61: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  for (int i = 0; i <= l; ++i) C[i] = 1ll * A[i] * B[i] % P; dft(C, -1, l);
                                                             ^~~