X 21 Let f : (0, ) R and f : (0, ) R be defined by f(x) = f(t-j)' dt, x>0 and 0 =1 f(x) = 98(x - 1)50-600(x - 1)4 +2450, x > 0, where, for any positive integer n and real numbers a, a2, ...., ans; denotes the product of a, a, ...., .. Let m; and n, respectively, denote the number of a i=1 points of local minima and the number of points of local maxima of function fi, i = 1, 2, in the interval (0, o). The value of 2m + 3n + mini is