710 B | 710 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
BLANK = " "
#inp = input
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
n = ii()
l = [input().split() for _ in range(n)]
l.sort(key = lambda t : (-int(t[1]), t[0]))
s = []
d = {}
for i in l:
if d.get(i[2], 0) == 0:
d[i[2]] = 1
s.append(i[0])
p(len(s))
s.sort()
p(*s, sep="\n")
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()