#include<algorithm>
using namespace std;
int n,m,k;
char s[2000001];
void solve(){
	int i,x,y,nr,sum;
    scanf("%d%d%d",&n,&m,&k);
    for(i=1; i<=m; ++i){
        scanf("%d%d",&x,&y);
        s[x]='1';
        s[y]='2';}
    for(i=1,nr=sum=0; nr<k; ++i){
        if(s[i]=='1')
            sum+=1;
        else if(s[i]=='2')
            sum-=1;
        else if(!sum)
            ++nr;}
    printf("%d",i);}
int main(){
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    solve();
    return 0;}