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#include <cstdint>
#include <cstdio>
#include <ranges>
#include <set>

struct Range {
  Range(const uint64_t l, const uint64_t r) : left(l), right(r) {}
  bool operator<(const Range& range) const { return left < range.left; }

  uint64_t left, right;
};

std::set<Range> merge(const std::set<Range>& ranges) {
  std::set<Range> outRanges;
  std::optional<Range> lastRange;
  for (const auto& range : ranges) {
    if (lastRange.has_value()) {
      if (lastRange->right + 1 == range.left) {
        lastRange->right = range.right;
      } else {
        outRanges.insert(lastRange.value());
        lastRange = range;
      }
    } else {
      lastRange = range;
    }
  }
  outRanges.insert(lastRange.value());
  return outRanges;
}

std::optional<uint64_t> fromLeft(const uint64_t n, const uint64_t s, std::set<Range>& ranges) {
  std::optional<uint64_t> result;
  for (const auto& range : ranges) {
    if (s < range.left) {
      break;
    } else if (1 < range.left) {
      result = range.left - 1;
    }
  }
  return result;
}

std::optional<uint64_t> fromRight(const uint64_t n, const uint64_t s, std::set<Range>& ranges) {
  std::optional<uint64_t> result;
  for (const auto& range : ranges | std::views::reverse) {
    if (range.right < s) {
      break;
    } else if (range.right < n) {
      result = range.right + 1;
    }
  }
  return result;
}

int main() {
  std::set<Range> ranges;
  uint64_t n, m, s, l, r;
  scanf("%lu %lu %lu\n", &n, &m, &s);
  for (int i = 0; i < m; ++i) {
    scanf("%lu %lu\n", &l, &r);
    ranges.emplace(l, r);
  }
  ranges = merge(ranges);
  const auto left = fromLeft(n, s, ranges);
  const auto right = fromRight(n, s, ranges);
  if (left.has_value() && right.has_value()) {
    if (s - left.value() <= right.value() - s) {
      printf("%lu\n", left.value());
    } else {
      printf("%lu\n", right.value());
    }
  } else if (left.has_value()) {
    printf("%lu\n", left.value());
  } else if (right.has_value()) {
    printf("%lu\n", right.value());
  }
  return 0;
}