from io import DEFAULT_BUFFER_SIZE
import sys

poly = None
inserters = {}

class polyme:
    def __init__(self, initial):
        self.Polymere = []
        self.letters = {}
        self.dubles = {}
        for f in initial:
            self.Polymere.append(f)
        for i in range(len(self.Polymere)):
            if i != len(self.Polymere) - 1:
                temp = self.Polymere[i] + self.Polymere[i + 1]
                g = self.dubles.setdefault(temp, 0)
                g += 1
                self.dubles.update({temp : g})
            temp2 = self.letters.setdefault(self.Polymere[i], 0)
            temp2 += 1
            self.letters.update({self.Polymere[i] : temp2})
        print(self.letters, self.dubles, self.Polymere)

    def steppy(self):
        tempdict = {}
        tempdict.clear()
        print(tempdict)
        for key, insert in inserters.items():
            if key in self.dubles:
                count = self.dubles[key]
                if insert in self.letters:
                    adletters = self.letters[insert]
                else:
                    adletters = 0
                adletters += count
                self.letters.update({insert : adletters})
                dub1 = key[0] + insert
                dub2 = insert + key[1]
                g = tempdict.setdefault(dub1, 0)
                g += count
                tempdict.update({dub1 : g})
                g = tempdict.setdefault(dub2, 0)
                g += count
                tempdict.update({dub2 : g})
                g = tempdict.setdefault(key, 0)
                g -= count
                tempdict.update({key : g})
        for dub, amount in tempdict.items():
            g = self.dubles.setdefault(dub, 0)
            g += amount
            self.dubles.update({dub : g})
        print(self.letters, self.dubles, self.Polymere)
        

    def findsolu(self):
        temp = self.letters.values()
        print(temp)
        temp2 = max(temp) - min(temp)
        return temp2
    
with open(sys.argv[1], 'r') as f:
    for g in f.readlines():
        g = g.strip()
        if poly is None:
            poly = polyme(g)
            continue
        if g == '':
            continue
        else:
            temp1, temp2 = g.split(' -> ')
            inserters.update({temp1:temp2})

for i in range(40):
    poly.steppy()

print(poly.findsolu())