import itertools as it
import operator as op
import functools as fn

print(sum(map(all, map(fn.partial(map, fn.partial(op.eq, 'T')), map(fn.partial(map, op.itemgetter(1)), map(op.itemgetter(1), it.groupby(zip(it.chain.from_iterable(map(fn.partial(it.repeat, times=int(input())//10), it.count())), input()), op.itemgetter(0))))))))

1
2
3
4
5

import itertools as it
import operator as op
import functools as fn

print(sum(map(all, map(fn.partial(map, fn.partial(op.eq, 'T')), map(fn.partial(map, op.itemgetter(1)), map(op.itemgetter(1), it.groupby(zip(it.chain.from_iterable(map(fn.partial(it.repeat, times=int(input())//10), it.count())), input()), op.itemgetter(0))))))))