#!/usr/bin/python3


def past_verb(v):
    vdict = {"be": "been", "go": "gone", "put": "put", "picnic": "picnicked"}
    pp = v +"ed"
    if v in vdict:
        pp = vdict[v]
    else:
        if v[-1] is 'e':
            pp = v + "d"
        elif v[-1] is 'y':
            if len(v) > 2 and v[-2] not in "aeiou":
                pp = v[0:-1] + "ied"
        elif v[-1] not in "aeiou":
          if len(v) > 2 and v[-2] in "aeiou":
            if len(v) > 3 and v[-3] not in "aeiou":
              pp = v + v[-1] + "ed"
    return pp

print(past_verb("play"))
print(past_verb("like"))
print(past_verb("try"))
print(past_verb("stop"))
print(past_verb("heat"))
print(past_verb("picnic"))
print(past_verb("go"))
print(past_verb("put"))