4.2_k_r

f = open("data.txt", 'r')
d = open("result.txt", 'w')
s1 = f.read()
s2 = s1
count = 0
start = -2
f.close()
for i in s1:
    if(i=='\n'):
        count+=1
while(count > 0):
    str1max = s2[0:s2.find('\n')]
    str1min = s2[0:s2.find('\n')]
    count -= 1
    s2=s2[s2.find('\n')+1:]
    lesson = str1max[str1max.find('-') + 2:str1max.find(':')]
    mark = minmark = maxmark = int(str1max[str1max.find(':') + 1:len(str1max)])
    i = 0
    while(lesson in s2):
        count-=1
        while(i != s2.find(lesson)):
            if(s2[i]=='\n'):
                start = i
            i+=1
        if(start == -2):
            str2 = s2[0:s2.find('\n')+1]
            s2=s2[s2.find('\n')+1:]
        else:
            str2 = s2[start:s2.find('\n', start + 2)]
            s2 = s2[0:start] + s2[s2.find('\n', start + 2):]
        mark = int(str2[str2.find(':')+1:])
        if(mark>maxmark):
            str1max = str2
            maxmark = mark
        elif(mark<minmark):
            str1min = str2
            minmark = mark

    start = -2;
    if(str1min!=str1max):
        d.write(str1max)
        d.write('\n')
        d.write(str1min)
    else:
        d.write(str1min)
        d.write('\n')
d.close()