#include <iostream>
#include <string.h>

int main(void){
	int n;
	std::cin >> n;
	int endmax = 0;

	int* pn = new int[100000];
	memset(pn, 0, 100000 * sizeof(int));

	for(int i=0; i<n; i++){
		int beg, end;
		std::cin >> beg >> end;
		for(int i = beg; i <= end; i++) pn[i]++;
		if(end > endmax) endmax = end;
	}

	int mps = 1;
	for(int i=1; i<=endmax; i++){\
		if(pn[i]+1 >= i)mps = i;
	}

	std::cout << (mps-1) << '\n';
	return 0;
}