import sys
class Ed:
    def __init__(self,p):
        self.p=p; self.s=open(p,'rb').read().decode('utf-8')
    def rep(self,old,new,count=1):
        old=old.replace('\r\n','\n').replace('\n','\r\n'); new=new.replace('\r\n','\n').replace('\n','\r\n')
        c=self.s.count(old)
        assert c==count,(c,old[:100])
        self.s=self.s.replace(old,new)
    def save(self):
        open(self.p,'wb').write(self.s.encode('utf-8'))