// Slower C++ solution:
#include <bits/stdc++.h>

using namespace std;

using ll = long long;

#define REP(i, n) for (int i = 0; i < (n); ++i)

#define SORT(v) sort((v).begin(),(v).end())

#define RSORT(v) sort((v).rbegin(),(v).rend())

const ll MOD = 1000000007;



ll gcd(ll a, ll b)

{

    if (b == 0)

        return a;

    return gcd(b, a % b);

}



ll lcm(ll a, ll b)

{

    ll g = gcd(a, b);

    return a / g * b;

}



ll mulMod(ll a, ll b)

{

    return (((a % MOD) * (b % MOD)) % MOD);

}







void solve(long long N, long long K, std::vector<long long> a, std::vector<long long> b){



}



int main(){

    long long N;

    scanf("%lld",&N);

    long long K;

    scanf("%lld",&K);

    ll cnt=0;

    vector<ll> A(100001);

    for(int i = 0 ; i < N ; i++){

        ll a,b;

        cin >> a >> b;

        A[a] = A[a] + b;

    }

    for(int i = 0; i < 100001; i++)

    {

        cnt += A[i];

        if(K <= cnt){

            cout << i << endl;

            return 0;

        }

    }

    

    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 1.7939132710775862x):
#include <bits/stdc++.h>

using namespace std;

using ll = long long;

using Edge = int;

using Graph = vector<vector<Edge>>;

#define REP(i, n) for (int i = 0; i < (n); ++i)

#define SORT(v) sort((v).begin(), (v).end())

#define RSORT(v) sort((v).rbegin(), (v).rend())

const ll MOD = 1000000007;

const ll nmax = 8;

const ll INF = 1e9;

const int MAX = 510000;

bool graph[nmax][nmax];

long long fac[MAX], finv[MAX], inv[MAX];



void COMinit()

{

    fac[0] = fac[1] = 1;

    finv[0] = finv[1] = 1;

    inv[1] = 1;

    for (int i = 2; i < MAX; i++)

    {

        fac[i] = fac[i - 1] * i % MOD;

        inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;

        finv[i] = finv[i - 1] * inv[i] % MOD;

    }

}



ll COM(int n, int k)

{

    if (n < k)

        return 0;

    if (n < 0 || k < 0)

        return 0;



    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;

}



vector<vector<ll>> dist = vector<vector<ll>>(nmax, vector<ll>(nmax, INF));

struct SegmentTree

{

private:

    ll n;

    vector<ll> node;



public:

    SegmentTree(vector<ll> v)

    {

        ll sz = v.size();

        n = 1;

        while (n < sz)

        {

            n *= 2;

        }

        node.resize(2 * n - 1, INF);



        for (ll i = 0; i < sz; i++)

        {

            node[i + n - 1] = v[i];

        }



        for (ll i = n - 2; i >= 0; i--)

        {

            node[i] = min(node[2 * i + 1], node[2 * i + 2]);

        }

    }

    void update(ll x, ll val)

    {

        x += (n - 1);

        node[x] = val;

        while (x > 0)

        {

            x = (x - 1) / 2;

            node[x] = min(node[2 * x + 1], node[2 * x + 2]);

        }

    }



    // findは半開区間で考える

    ll find(ll a, ll b, ll k = 0, ll l = 0, ll r = -1)

    {

        if (r < 0)

            r = n;



        if (r <= a || b <= l)

            return INF;



        if (a <= l && r <= b)

            return node[k];



        ll vl = find(a, b, 2 * k + 1, l, (l + r) / 2);

        ll vr = find(a, b, 2 * k + 2, (l + r) / 2, r);

        return min(vl, vr);

    }

};

void warshall_floyd(ll n)

{

    for (size_t i = 0; i < n; i++)

    {

        for (size_t j = 0; j < n; j++)

        {

            for (size_t k = 0; k < n; k++)

            {

                dist[j][k] = min(dist[j][k], dist[j][i] + dist[i][k]);

            }

        }

    }

}



class UnionFind

{

public:

    vector<ll> Parent;



    UnionFind(ll N)

    {

        Parent = vector<ll>(N, -1);

    }

    ll find(ll A)

    {

        if (Parent[A] < 0)

            return A;

        return Parent[A] = find(Parent[A]);

    }



    ll size(ll A)

    {

        return -Parent[find(A)];

    }



    bool Union(ll A, ll B)

    {

        A = find(A);

        B = find(B);

        if (A == B)

        {

            return false;

        }

        if (size(A) < size(B))

            swap(A, B);



        Parent[A] += Parent[B];

        Parent[B] = A;



        return true;

    }

};



ll gcd(ll a, ll b)

{

    if (b == 0)

        return a;

    return gcd(b, a % b);

}



ll lcm(ll a, ll b)

{

    ll g = gcd(a, b);

    return a / g * b;

}



ll mulMod(ll a, ll b)

{

    return (((a % MOD) * (b % MOD)) % MOD);

}



ll powMod(ll a, ll p)

{

    if (p == 0)

    {

        return 1;

    }

    else if (p % 2 == 0)

    {

        ll half = powMod(a, p / 2);

        return mulMod(half, half);

    }

    else

    {

        return mulMod(powMod(a, p - 1), a);

    }

}



ll ceil(ll a, ll b)

{

    return (a + b - 1) / b;

}



vector<ll> tsort(Graph G)

{

    ll N = G.size();

    vector<ll> in(N);

    for (auto &&edges : G)

    {

        for (auto &&edge : edges)

        {

            in[edge]++;

        }

    }



    queue<int> que;



    for (int i = 0; i < N; i++)

    {

        if (in[i] == 0)

        {

            que.push(i);

        }

    }

    int cnt = 0;

    vector<ll> ans;

    while (!que.empty())

    {

        int v = que.front();

        que.pop();

        ans.push_back(v);

        for (auto &&next : G[v])

        {



            in[next]--;

            if (in[next] == 0)

            {

                que.push(next);

            }

        }

    }

    return ans;

}

Graph G(100);

void treeDFS(int from, int current, int dist, int &maxDist, int &maxVertex)

{

    if (dist > maxDist)

    {

        maxDist = dist;

        maxVertex = current;

    }



    for (auto to : G[current])

    {

        if (to == from)

            continue;

        treeDFS(current, to, dist + 1, maxDist, maxVertex);

    }

}



pair<int, int> getTreeDiameter()

{

    int start = 0, end = 0, maxDist = 0;

    treeDFS(-1, start, 0, maxDist, end);

    start = end, end = 0, maxDist = 0;

    treeDFS(-1, start, 0, maxDist, end);

    return make_pair(start, end);

}



void solve(long long N, long long K, std::vector<long long> a, std::vector<long long> b){

    ll cnt = 0;

    vector<pair<ll,ll>> c(N);

    for (int i = 0; i < N; i++)

    {

        c[i] = make_pair(a[i],b[i]);

    }

    SORT(c);



    for (int i = 0; i < N; i++)

    {

        cnt += c[i].second;

        if(K <= cnt){

            cout << c[i].first << endl;

            return;

        }

    }

    

    

}



int main(){

    long long N;

    scanf("%lld",&N);

    long long K;

    scanf("%lld",&K);

    std::vector<long long> a(N);

    std::vector<long long> b(N);

    for(int i = 0 ; i < N ; i++){

        scanf("%lld",&a[i]);

        scanf("%lld",&b[i]);

    }

    solve(N, K, std::move(a), std::move(b));

    return 0;

}