The common difference of the A.P.: \( a_1, a_2, \ldots, a_m \) is \( 13 \) more than the common difference of the A.P.: \( b_1, b_2, \ldots, b_n \). If \( b_{31} = -277 \), \( b_{43} = -385 \) and \( a_{78} = 327 \), then \( a_1 \) is equal to:
\( 24 \)
\( 21 \)
\( 16 \)
\( 19 \)
