[백준][Python] 1946번 신입 사원

import sys
T = int(sys.stdin.readline())
for t in range(T):
    n = int(sys.stdin.readline())
    score = []
    for _ in range(n):
        score.append(list(map(int,sys.stdin.readline().split())))
    score = sorted(score,key=lambda x : x[0])
    min_value = score[0][1]
    count = 1
    for i in range(1,len(score)):
        if score[i][1] < min_value:
            count += 1
            min_value = score[i][1]
    print(count)