#include <bits/stdc++.h>

using namespace std;
struct ceva
{
    int st,dr;
}v[100003];
bool ctr(ceva x,ceva y)
{
    if(x.st!=y.st)
        return x.st<y.st;
    else
        return x.dr<y.dr;
}
bool intersec(int x,int y,int xx,int yy)
{
    if(xx>=x and xx<=y)
        return 1;
    return 0;
}
int n ,m,k,cnt;
int main()
{
    cin>>n>>m>>k;
    for(int i=1;i<=m;i++)
    {
        cin>>v[i].st>>v[i].dr;
    }
    for(int i=m;i>=1;i--)
    {
        if(k>=v[i].st)
            k+=v[i].dr-v[i].st+1;
    }
    cout<<k;
    return 0;
}