#include <bits/stdc++.h>

using namespace std;

#define rint int

#define IL inline

#define rep(i,h,t) for (rint i=h;i<=t;i++)

#define dep(i,t,h) for (rint i=t;i>=h;i--)

#define me(x) memset(x,0,sizeof(x))

#define ll long long

const int N=;

const int INF=1e9;

int n,m,k;

int f[N],g[N][N][],maxa,p[N];

IL void minn(rint& x,rint y)

{

  if (x>y) x=y;

}

struct re{

  int a,b;

}a[N];

IL bool cmp(re x,re y)

{

  return x.a<y.a;

}

int main()

{

  freopen("1.in","r",stdin);

  freopen("1.out","w",stdout);

  ios::sync_with_stdio(false);

  cin>>n>>m>>k;

  int maxa=;

  rep(i,,m)

  {

    cin>>a[i].a>>a[i].b;

  }

  sort(a+,a+m+,cmp);

  a[].a=INF;

  int cnt=;

  rep(i,,m)

  {

    if (a[i].a!=a[i-].a) cnt++;

    f[cnt]=max(f[cnt],a[i].b);

    p[cnt]=a[i].a;

  }

  maxa=cnt+; p[maxa]=p[maxa-];

  rep(i,,N-)

    rep(j,,N-) g[i][j][]=g[i][j][]=INF;

  g[][maxa][]=;

  dep(i,maxa,)

    rep(j,,maxa-i)

    {

      rint k=j+i;

      if (g[j][k][]!=INF)

        minn(g[j+][k][],max(g[j][k][]+p[j+]-p[j],f[j+])),

        minn(g[j][k-][],max(g[j][k][]+p[k-]-p[j],f[k-]));

      if (g[j][k][]!=INF )

        minn(g[j][k-][],max(g[j][k][]+p[k]-p[k-],f[k-])),

        minn(g[j+][k][],max(g[j][k][]+p[k]-p[j+],f[j+]));

    }

  int ans=INF;

  rep(i,,maxa)

    ans=min(ans,abs(p[i]-k)+min(g[i][i][],g[i][i][]));

  cout<<ans<<endl;

  return ;

}