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import sys
from collections import deque


def a(l, r, blocked):
    for i in range(l, r + 1):
        blocked[i] = True


n, m, s = map(int, sys.stdin.readline().split())
blocked = [False] * (n + 1)

for _ in range(m):
    l, r = map(int, sys.stdin.readline().split())
    a(l, r, blocked)

# BFS do znalezienia najbliższego nieblokowanego numeru
queue = deque([s])
visited = set([s])

while queue:
    x = queue.popleft()

    if not blocked[x]:
        print(x)
        break

    if x - 1 >= 1 and x - 1 not in visited:
        queue.append(x - 1)
        visited.add(x - 1)

    if x + 1 <= n and x + 1 not in visited:
        queue.append(x + 1)
        visited.add(x + 1)