594 B | 594 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
input()
n, e = mii()
l = [ii() for _ in range(e)]
d = {}
for i in range(1, n + 1):
d[i] = i
k = 0
for i in l:
d[i] = k
k -= 1
return sorted(d.items(), key = lambda t : (-t[1]))[0][0]
if __name__ == "__main__":
tc = ii()
for t in range(1, tc+1):
ret = solve()
p(ret)