Let f1 : (0, $\infty$) $\to$ R and f2 : (0, $\infty$) $\to$ R be defined by $${f_1}(x) = \int\limits_0^x {\prod\limits_{j = 1}^{21} {{{(t - j)}^j}dt} }$$, x > 0 and $${f_2}(x) = 98{(x - 1)^{50}} - 600{(x - 1)^{49}} + 2450,x \gt 0$$, where, for any positive integer n and real numbers a1, a2, ....., an, $\prod olimits_{i = 1}^n {{a_i}}$ denotes the product of a1, a2, ....., an. Let mi and ni, respectively, denote the number of points of local minima and the number of points of local maxima of function fi, i = 1, 2 in the interval (0, $\infty$). The value of $6{m_2} + 4{n_2} + 8{m_2}{n_2}$ is $\underline{\hspace{2cm}}$.