#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<ctime>

#include<algorithm>

#include<cstdlib>

#include<map>

#include<set>

#include<vector>

#include<queue>

#include<cmath>

using namespace std;

#define FILE "a"

#define LL long long

#define up(i,j,n) for(int i=j;i<=n;i++)

#define pii pair<int,int>

#define piii pair<int,pii >

template<typename T> inline bool chkmin(T &a,T b){return a>b?a=b,true:false;}

template<typename T> inline bool chkmax(T &a,T b){return a<b?a=b,true:false;}

namespace IO{

    char *fs,*ft,buf[<<];

    inline char gc(){return (fs==ft&&(ft=(fs=buf)+fread(buf,,<<,stdin),fs==ft))?:*fs++;}

    inline int read(){

        LL x=;int ch=gc();bool f=;

        while(ch<''||ch>''){if(ch=='-')f=;ch=gc();}

        while(ch<=''&&ch>=''){x=(x<<)+(x<<)+ch-'';ch=gc();}

        return f?-x:x;

    }

}using namespace IO;

namespace OI{

    const int maxn();

    struct node{

        int x,y;

        bool operator<(const node &b)const{return x<b.x||(x==b.x&&y<b.y);}

        bool operator==(const node &b){return x==b.x&&y==b.y;}

    }a[maxn];

    int n,f[maxn];

    struct Node{

        int y,v,next;

    }e[maxn];

    int linkk[maxn],len=;

    void insert(int x,int y,int v){

        e[++len].y=y;

        e[len].next=linkk[x];

        linkk[x]=len;

        e[len].v=v;

    }

    void slove(){

        n=read();

        up(i,,n)a[i].x=read()+,a[i].y=n-read();

        sort(a+,a+n+);

        up(i,,n){

            int j=i,v;

            while(a[j+]==a[i])j++;

            v=j-i+;

            if(a[i].y-a[i].x+<v)v=a[i].y-a[i].x+;

            insert(a[i].x,a[i].y,v);

            i=j;

        }

        up(i,,n){

            chkmax(f[i],f[i-]);

            for(int j=linkk[i];j;j=e[j].next)chkmax(f[e[j].y],f[i-]+e[j].v);

        }

        printf("%d\n",n-f[n]);

    }

}

int main(){

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

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

    using namespace OI;

    slove();

    return ;

}