Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const (
	MAX_N      = 100
	MAX_WEIGHT = 100000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	shortestList := make([]ShortestInfo, n)
	for i := 1; i < n; i++ {
		shortestList[i] = ShortestInfo{edges: []Edge{}, shortest: MAX_N*MAX_WEIGHT + 1}
	}

	adjacentMatrix, err := createAdjacentMatrix(n, sc)
	if err != nil {
		panic(err)
	}

	sssp([]int{1}, shortestList, adjacentMatrix)
	for _, v := range shortestList {
		fmt.Printf("%d %d\n", v.getEnd()-1, v.shortest)
	}
}

func (si ShortestInfo) getEnd() int {
	if len(si.edges) == 0 {
		return 1
	} else {
		return si.edges[len(si.edges)-1].end
	}
}

func createAdjacentMatrix(n int, sc *bufio.Scanner) ([][]int, error) {
	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		adjacentMatrix[id] = make([]int, n)
		for j := 0; j < n; j++ {
			adjacentMatrix[id][j] = -1
		}
		vertexNum, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		for j := 0; j < vertexNum; j++ {
			v, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			c, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			adjacentMatrix[id][v] = c
		}
	}
	return adjacentMatrix, nil
}

func sssp(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	for len(nodeStack) > 0 {
		currentNode := nodeStack[0]
		nodeStack = nodeStack[1:]
		currentShortest := getShortest(currentNode, shortestList)
		adjacents := findAdjacents(currentNode, adjacentMatrix)
		for i := 0; i < len(adjacents); i++ {
			adj := adjacents[i]
			if currentShortest.shortest+adj.weight < getShortest(adj.end, shortestList).shortest {
				setShortest(adj.end, adj, currentShortest, shortestList)
				nodeStack = append(nodeStack, adj.end)
			}
		}
	}
}

func getShortest(node int, shortestList []ShortestInfo) ShortestInfo {
	return shortestList[node-1]
}

func setShortest(node int, edge Edge, currentShortest ShortestInfo, shortestList []ShortestInfo) {
	newEdges := make([]Edge, len(currentShortest.edges)+1)
	for i := 0; i < len(newEdges)-1; i++ {
		newEdges[i] = currentShortest.edges[i]
	}
	newEdges[len(newEdges)-1] = edge
	shortestInfo := ShortestInfo{edges: newEdges, shortest: currentShortest.shortest + edge.weight}
	shortestList[node-1] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode-1]
	edges := []Edge{}
	for i, v := range adjacents {
		if v > 0 {
			edges = append(edges, Edge{start: currentNode, end: i + 1, weight: v})
		}
	}
	return edges
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: // AtCoder template
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i = 0; i < n; ++i)

/*
* グラフ構造体
*/
template<typename U>
struct edge{
    int to;
    int from;
    U cost; // 変更
    edge(int to, int from, U cost):to(to), from(from), cost(cost){}
    edge(int to, int from):to(to), from(from), cost(1){}
};

template<typename T>
class Graph{
public:
    vector<vector<edge<T>>> graph;
    int v_size;
    
    // 無向グラフならunDirected = true
    Graph(int n, vector<int> from, vector<int> to, vector<T> cost, bool unDirected){
        if(from.size() != to.size() || to.size() != cost.size()) cout << "Graph constructer detected error.\n";
        graph.assign(n, vector<edge<T>>());
        v_size = n;
        for(int i = 0; i < from.size(); ++i){
            edge<T> tmp(to[i], from[i], cost[i]);
            graph[from[i]].push_back(tmp);
            if(unDirected){
                swap(tmp.from, tmp.to);
                graph[to[i]].push_back(tmp);
            }
        }
    }
    Graph(int n, vector<int> from, vector<int> to, bool unDirected){
        if(from.size() != to.size()) cout << "Graph constructer detected error.\n";
        graph.assign(n, vector<edge<T>>());
        for(int i = 0; i < from.size(); ++i){
            edge<T> tmp(to[i], from[i]);
            graph[from[i]].push_back(tmp);
            if(unDirected){
                swap(tmp.from, tmp.to);
                graph[to[i]].push_back(tmp);
            }
        }
    }

    // BFS, DFS
    vector<bool> visited;
    bool BFS(int start, int goal){
        visited.assign(graph.size(), false);
        queue<pair<int, T>> que;
        que.emplace(start, 0);
        while(!que.empty()){
            int now = que.front().first;
            T depth = que.front().second;
            que.pop();
            visited[now] = true;
            
            if(now == goal){ // 処理記述

                return true;
            }
            
            for(int i = 0; i < graph[now].size(); ++i){
                int next = graph[now][i].to;
                int cost = graph[now][i].cost;
                if(visited[next]) continue;
                que.emplace(next, depth+cost);
            }
        }
        return false;
    }

    bool DFS(int start, int goal){
        visited.assign(v_size, false);
        stack<pair<int, T>> sta;
        sta.emplace(start, 0);
        while(!sta.empty()){
            int now = sta.top().first;
            T depth = sta.top().second;
            sta.pop();
            visited[now] = true;
    
            if(now == goal){ // 処理記述
                
                return true;
            }
            for(int i = 0; i < graph[now].size(); ++i){
                int next = graph[now][i].to;
                int cost = graph[now][i].cost;
                if(visited[next]) continue;
                sta.emplace(next, depth+cost);
            }
        }
        return false;
    }
    
    // ダイクストラ法（による最短経路木構築）
    vector<T> d_d;
    void Dijkstra(int start, int goal, T t_max){
        d_d.assign(graph.size(), t_max);
        d_d[start] = 0;
        priority_queue<pair<T,int>, vector<pair<T,int>>, greater<pair<T, int>> > que;
        que.emplace(0, start);
        while(!que.empty()){
            T dist = que.top().first;
            int now = que.top().second;
            que.pop();
            if(d_d[now] < dist) continue;
            //if(now == goal) return ; // ここの行を失くせばstart全頂点への距離が求められる
            for(int i = 0; i < graph[now].size(); ++i){
                int next = graph[now][i].to;
                int next_cost = graph[now][i].cost;
                if(d_d[next] > d_d[now] + next_cost){
                    d_d[next] = d_d[now] + next_cost;
                    que.emplace(d_d[next], next);
                }
            }
        }
    }

    // ワーシャルフロイド法
    vector<vector<T>> w_d;
    void Warshal_Floyd(T u_max){
        int n = graph.size();
        w_d.assign(n, vector<T>(n, u_max));
        for(int i = 0; i < n; ++i){
            w_d[i][i] = 0;
            for(int j = 0; j < graph[i].size(); ++j){
                int next = graph[i][j].to, dist = graph[i][j].cost;
                w_d[i][next] = dist;
            }
        }
        for(int i = 0; i < n ; ++i){
            for(int j = 0; j < n; ++j){
                for(int k = 0; k < n; ++k){
                    w_d[j][k] = min(w_d[j][k], w_d[j][i] + w_d[i][k]);
                }
            }
        }
    }
};




int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n; cin >> n;
    vector<int> from,to;
    vector<ll> cost;
    rep(i,n){
        int u,k; cin >> u >> k;
        rep(j,k){
            int v,c; cin >> v >> c;
            from.push_back(u);
            to.push_back(v);
            cost.push_back(c);
        }
    }
    Graph<ll> graph(n, from, to, cost, false);
    graph.Dijkstra(0, 0, INT_MAX);
    rep(i,n) cout << i << " " << graph.d_d[i] << "\n";
}