from operator import *
def pay(m, w):
  r = dict()
  m = sum((k*w[k] for k in w)) - m
  if m < 0: raise "money"
  for c in (500,100,50,10,5,1):
    r[c] = w.get(c, 0) - m / c
    m %= c
  return dict(((k,v) for k,v in r.items() if v > 0))