[ Diff(x[1], t) = (1*k[66]*ceil(sin(Pi*t/k[65] + 1/1000)/2)*k[1]*x[13] + 1*k[66]*k[2]*x[9]^k[3]/(k[4]^k[3] + x[9]^k[3]) + (-1)*k[66]*k[5]*x[1]/(k[6] + x[1]))/k[66],
  Diff(x[2], t) = (1*k[66]*k[7]*x[1] + 1*k[66]*k[9]*x[3] + (-1)*k[66]*k[10]*x[2]/(k[11] + x[2]) + (-1)*k[66]*k[8]*x[2])/k[66],
  Diff(x[3], t) = ((-1)*k[66]*k[9]*x[3] + 1*k[66]*k[8]*x[2] + (-1)*k[66]*k[12]*x[3]/(k[13] + x[3]))/k[66],
  Diff(x[4], t) = (1*k[66]*k[14]*x[12]^k[15]/(k[16]^k[15] + x[12]^k[15])*k[17]^k[18]/(k[17]^k[18] + x[3]^k[18]) + (-1)*k[66]*k[19]*x[4]/(k[20] + x[4]))/k[66],
  Diff(x[5], t) = (1*k[66]*k[21]*x[4] + 1*k[66]*k[23]*x[6] + (-1)*k[66]*((1 - ceil(sin(Pi*t/k[65] + 1/1000)/2))*k[24] + k[25])*x[5]/(k[26] + x[5]) + (-1)*k[66]*k[22]*x[5])/k[66],
  Diff(x[6], t) = ((-1)*k[66]*k[23]*x[6] + 1*k[66]*k[22]*x[5] + (-1)*k[66]*((1 - ceil(sin(Pi*t/k[65] + 1/1000)/2))*k[27] + k[28])*x[6]/(k[29] + x[6]))/k[66],
  Diff(x[7], t) = (1*k[66]*k[30]*x[6]^k[31]/(k[32]^k[31] + x[6]^k[31]) + (-1)*k[66]*k[33]*x[7]/(k[34] + x[7]))/k[66],
  Diff(x[8], t) = (1*k[66]*k[35]*x[7] + 1*k[66]*k[37]*x[9] + (-1)*k[66]*k[38]*x[8]/(k[39] + x[8]) + (-1)*k[66]*k[36]*x[8])/k[66],
  Diff(x[9], t) = ((-1)*k[66]*k[37]*x[9] + 1*k[66]*k[36]*x[8] + (-1)*k[66]*k[40]*x[9]/(k[41] + x[9]))/k[66],
  Diff(x[10], t) = (1*k[66]*(ceil(sin(Pi*t/k[65] + 1/1000)/2)*k[42]*x[13] + (ceil(sin(Pi*t/k[65] + 1/1000)/2)*k[43] + k[44])*k[45]^k[48]/(k[45]^k[48] + x[6]^k[48]))*k[46]^k[47]/(k[46]^k[47] + x[3]^k[47]) + (-1)*k[66]*k[49]*x[10]/(k[50] + x[10]))/k[66],
  Diff(x[11], t) = (1*k[66]*k[51]*x[10] + 1*k[66]*k[53]*x[12] + (-1)*k[66]*k[54]*x[11]/(k[55] + x[11]) + (-1)*k[66]*k[52]*x[11])/k[66],
  Diff(x[12], t) = ((-1)*k[66]*k[53]*x[12] + 1*k[66]*k[52]*x[11] + (-1)*k[66]*k[56]*x[12]/(k[57] + x[12]))/k[66],
  Diff(x[13], t) = (1*k[66]*(1 - ceil(sin(Pi*t/k[65] + 1/1000)/2))*k[58] + (-1)*k[66]*k[61]*x[13]/(k[59] + x[13]) + (-1)*k[66]*k[60]*ceil(sin(Pi*t/k[65] + 1/1000)/2)*x[13])/k[66] ]