#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

const int u=10000;

int n;

int father[u+1];

int isinc[u+1];

int siz[u+1];

int Getf(int x){

	if(father[x]==x)return x;

	return father[x]=Getf(father[x]);

}

void Unionn(int x,int y){

	int fx=Getf(x);

	int fy=Getf(y);

	if(fx!=fy){

		father[fx]=fy;

		siz[fy]+=siz[fx];

		isinc[fy]=isinc[fy]|isinc[fx];

	}

}

int main(){

	for(int i=1;i<=u;++i)father[i]=i;

	for(int i=1;i<=u;++i)siz[i]=1;

	scanf("%d",&n);

	while(n--){

		int x,y;

		scanf("%d%d",&x,&y);

		if(Getf(x)==Getf(y)){

			isinc[Getf(x)]=1;

		}else{

			Unionn(x,y);

		}

	}

	for(int i=1;i<=u;++i){

		int f=Getf(i);

		if(isinc[f])continue;

		if(siz[f]==1){

			printf("%d\n",i-1);

			return 0;

		}

		--siz[f];

	}

	printf("%d\n",u);

	return 0;

}