balance = 3926
annualInterestRate = 0.2
monthlyInterestRate = annualInterestRate/12
mmp = 10
m = 1
while(balance > 0):
      balance = 3926
      m = 1
      mmp += 10
      while(m <=12):
           m +=  1
           balance = (balance - mmp)*(1 + monthlyInterestRate)
if(balance <= 0 and mmp > 0):
     print 'Lowest Payment: ', mmp

Lowest Payment:  360