{ diff(x1, t) = ((-1)*k7*x2*x1 + 1*k9*x3 + 1*k8*x3 + (-1)*k10*x6*x1 + 1*k12*x7 + 1*k11*x7 + (-1)*k13*x9*x1 + 1*k15*x10 + 1*k14*x10 + (-1)*k1*x5*x1 + 1*k2*x12 + 1*k16*x12 + (-1)*k3*x8*x1 + 1*k4*x13 + 1*k17*x13 + (-1)*k5*x11*x1 + 1*k6*x14 + 1*k18*x14 + 1*k20*x18 + (-1)*k19*x1)/k65,
  diff(x2, t) = ((-1)*k7*x2*x1 + 1*k8*x3 + 1*k34*x4*x5 + (-1)*k62*x2 + (-1)*k35*x2)/k65,
  diff(x3, t) = (1*k7*x2*x1 + (-1)*k9*x3 + (-1)*k8*x3 + 1*k52*x4*x12 + (-1)*k53*x3)/k65,
  diff(x4, t) = (1*k9*x3 + (-1)*k34*x4*x5 + 1*k62*x2 + 1*k35*x2 + 1*k12*x7 + (-1)*k40*x4*x8 + 1*k63*x6 + 1*k41*x6 + 1*k15*x10 + (-1)*k46*x4*x11 + 1*k64*x9 + 1*k47*x9 + (-1)*k52*x4*x12 + 1*k53*x3 + (-1)*k55*x4*x13 + 1*k56*x7 + (-1)*k58*x4*x14 + 1*k59*x10 + (-1)*k61*x4)/k65,
  diff(x5, t) = ((-1)*k34*x4*x5 + 1*k35*x2 + (-1)*k1*x5*x1 + 1*k2*x12 + 1*k39*x19 + (-1)*k38*x5 + 1*k36*x16 + (-1)*k37*x5)/k65,
  diff(x6, t) = ((-1)*k10*x6*x1 + 1*k11*x7 + 1*k40*x4*x8 + (-1)*k63*x6 + (-1)*k41*x6)/k65,
  diff(x7, t) = (1*k10*x6*x1 + (-1)*k12*x7 + (-1)*k11*x7 + 1*k55*x4*x13 + (-1)*k56*x7)/k65,
  diff(x8, t) = ((-1)*k40*x4*x8 + 1*k41*x6 + (-1)*k3*x8*x1 + 1*k4*x13 + 1*k45*x21 + (-1)*k44*x8 + 1*k42*x23 + (-1)*k43*x8)/k65,
  diff(x9, t) = ((-1)*k13*x9*x1 + 1*k14*x10 + 1*k46*x4*x11 + (-1)*k64*x9 + (-1)*k47*x9)/k65,
  diff(x10, t) = (1*k13*x9*x1 + (-1)*k15*x10 + (-1)*k14*x10 + 1*k58*x4*x14 + (-1)*k59*x10)/k65,
  diff(x11, t) = ((-1)*k46*x4*x11 + 1*k47*x9 + (-1)*k5*x11*x1 + 1*k6*x14 + 1*k51*x24 + (-1)*k50*x11 + 1*k48*x26 + (-1)*k49*x11)/k65,
  diff(x12, t) = ((-1)*k52*x4*x12 + 1*k53*x3 + 1*k1*x5*x1 + (-1)*k2*x12 + 1*k54*x20 + (-1)*k16*x12)/k65,
  diff(x13, t) = ((-1)*k55*x4*x13 + 1*k56*x7 + 1*k3*x8*x1 + (-1)*k4*x13 + 1*k57*x22 + (-1)*k17*x13)/k65,
  diff(x14, t) = ((-1)*k58*x4*x14 + 1*k59*x10 + 1*k5*x11*x1 + (-1)*k6*x14 + 1*k60*x25 + (-1)*k18*x14)/k65,
  diff(x15, t) = 0,
  diff(x16, t) = (1*k28*x18*x18 + (-1)*k29*x16 + 1*k27*k66)/k65,
  diff(x17, t) = 0,
  diff(x18, t) = ((-1)*k21*x19*x18 + 1*k22*x20 + (-1)*k23*x21*x18 + 1*k24*x22 + (-1)*k25*x24*x18 + 1*k26*x25 + (-1)*k20*x18 + 1*k19*x1)/k65,
  diff(x19, t) = ((-1)*k21*x19*x18 + 1*k22*x20 + (-1)*k39*x19 + 1*k38*x5)/k65,
  diff(x20, t) = (1*k21*x19*x18 + (-1)*k22*x20 + (-1)*k54*x20)/k65,
  diff(x21, t) = ((-1)*k23*x21*x18 + 1*k24*x22 + (-1)*k45*x21 + 1*k44*x8)/k65,
  diff(x22, t) = (1*k23*x21*x18 + (-1)*k24*x22 + (-1)*k57*x22)/k65,
  diff(x23, t) = ((-1)*k31*x23 + 1*k30*k66)/k65,
  diff(x24, t) = ((-1)*k25*x24*x18 + 1*k26*x25 + (-1)*k51*x24 + 1*k50*x11)/k65,
  diff(x25, t) = (1*k25*x24*x18 + (-1)*k26*x25 + (-1)*k60*x25)/k65,
  diff(x26, t) = ((-1)*k33*x26 + 1*k32*k66)/k65 }