#include<cstdio>
#include<algorithm>
using namespace std;
int n,m,k;
struct interval{int a,b;};
interval v[100001];
int main(){
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    scanf("%d%d%d",&n,&m,&k);
    for(int i=1;i<=m;i++)
        scanf("%d%d",&v[i].a,&v[i].b);
    for(int i=m;i>=1;i--)
        if(v[i].a<=k)
            k+=(v[i].b-v[i].a+1);
    printf("%d",k);
    return 0;
}