#include <bits/stdc++.h>

using namespace std;

int h1, m1, h2, m2;

int tim1 = , tim2 = ;

int main() {

    scanf("%d:%d", &h1, &m1);

    scanf("%d:%d", &h2, &m2);

    tim1 = h1 *  + m1;

    tim2 = h2 *  + m2;

    tim2 -= tim1;

    tim2 /= ;

    tim1 += tim2;

    int h3 = tim1 / , m3 = tim1 % ;

    printf("%02d:%02d\n", h3, m3);

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5 + ;

int N, K;

int a[maxn], vis[];

int main() {

    scanf("%d%d", &N, &K);

    int ans = , cnt = ;

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

        int x;

        scanf("%d", &x);

        if(x % K == ) ans ++;

        else vis[x % K] ++;

    }

    ans /= ;

    for(int i = ; i <= K / ; i ++) {

        if(i *  != K) ans += min(vis[i], vis[K - i]);

        else ans += (vis[i] / );

    }

    printf("%d\n", ans * );

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5 + ;

int N;

int a[maxn];

int main() {

    scanf("%d", &N);

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

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

    sort(a, a + N);

    int maxx = ;

    int l = , r = ;

    while(l <= r && r < N && l < N) {

        while(a[r] - a[l] <=  && r < N) r ++;

        maxx = max(maxx, r - l);

        l ++;

    }

    printf("%d\n", maxx);

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5 + ;

int N;

int a[maxn], b[maxn];

map<pair<int, int> , int> mp;

int gcd(int a, int b) {

    return b ==  ? a : gcd(b, a % b);

}

int main() {

    scanf("%d", &N);

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

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

    int cnt = , maxx = ;

    mp.clear();

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

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

        if(a[i] == ) {

            if(b[i] == ) cnt ++;

            continue;

        }

        int t = gcd(a[i], b[i]);

        pair<int, int> p;

        p.first = a[i] / t, p.second = b[i] / t;

        if(p.first < ) p.first *= -, p.second *= -;

        mp[p] ++;

        maxx = max(maxx, mp[p]);

    }

    printf("%d\n", maxx + cnt);

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = ;

int N, K;

int a[maxn], dp[maxn][maxn];

int main() {

    scanf("%d%d", &N, &K);

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

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

    sort(a + , a + N + );

    memset(dp, , sizeof(dp));

    int pos = ;

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

        while(a[i] - a[pos] >  && pos <= N) pos ++;

        for(int j = ; j <= min(K, i); j ++) {

            dp[i][j] = max(dp[i - ][j], dp[pos - ][j - ] + i - pos + );

        }

    }

    int ans = ;

    for(int i = ; i <= K; i ++) {

        ans = max(ans, dp[N][i]);

    }

    printf("%d\n", ans);

    return ;

}

#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5 + ;

int N, M;

vector<int> v[maxn];

int vis[maxn], son[maxn];

int maxx = , temp;

vector<int> u;

vector<vector<int> > ans;

void bfs(int st) {

    vis[st] = ;

    queue<int> q;

    while(!q.empty()) q.pop();

    q.push(st);

    while(!q.empty()) {

        int tp = q.front();

        q.pop();

        for(int i = ; i < v[tp].size(); i ++) {

            if(!vis[v[tp][i]]) {

                vis[v[tp][i]] = ;

                printf("%d %d\n", tp, v[tp][i]);

                q.push(v[tp][i]);

            }

        }

    }

}

int main() {

    scanf("%d%d", &N, &M);

    while(M --) {

        int a, b;

        scanf("%d%d", &a, &b);

        v[a].push_back(b);

        v[b].push_back(a);

        son[a] ++, son[b] ++;

    }

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

        if(son[i] > maxx) {

            maxx = son[i];

            temp = i;

        }

    }

    bfs(temp);

    return ;

}