#!/usr/bin/python
#
# Assign equal values to equal letters, and different values to
# different letters, in a way that satisfies the following sum:
#
#    TWO
#  + TWO
#  -----
#   FOUR
#
from constraint import *

def main():
    problem = Problem()
    problem.addVariables("twofur", range(10))
    problem.addConstraint(lambda o, r: (2*o)%10 == r, "or")
    problem.addConstraint(lambda w, o, u, r: ((10*2*w)+(2*o))%100 == u*10+r,
                          "wour")
    problem.addConstraint(lambda t, w, o, f, u, r:
                          2*(t*100+w*10+o) == f*1000+o*100+u*10+r, "twofur")
    problem.addConstraint(NotInSetConstraint([0]), "ft")
    problem.addConstraint(AllDifferentConstraint())
    print "TWO+TWO=FOUR"
    for s in problem.getSolutions():
        print "%(t)d%(w)d%(o)d+%(t)d%(w)d%(o)d=%(f)d%(o)d%(u)d%(r)d" % s

if __name__ == "__main__":
    main()