#include <stdio.h>
struct MyStruct {int x,y;};
MyStruct a[100005];
int main()
{
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    int i,n,m,k,x;
    scanf("%d%d%d",&n,&m,&k); x=k;
    for(i=1;i<=m;++i) scanf("%d%d",&a[i].x,&a[i].y);
    for(i=m;i>0;--i)
        if(x>=a[i].x) 
            x+=a[i].y-a[i].x+1;
    printf("%d",x);
    return 0;
}