#include <stdio.h>
int N,M,K,a[100005],b[100005];
int main(){
    int i,j,nr,cnt;
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    scanf("%d %d %d",&N,&M,&K);
    nr=N;cnt=0;
    while (M--){
      scanf("%d %d",&i,&j);
      if (i>nr) continue;
      if (j>nr) j=nr;
      nr-=(j-i+1);
      ++cnt;
      a[cnt]=i;
      b[cnt]=j;
      }
    while (cnt){
      i=a[cnt];
      j=b[cnt];
      --cnt;
      if (i>K) continue;
      K+=(j-i+1);
      }
    printf("%d",K);
    return 0;
}