#include <cassert>
#include <climits>
#include <algorithm>
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <queue>
#include <set>

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*/

class TVertex;
struct TPath
{
    int Cost;
    TVertex* Target;
    TPath(TVertex* ATarget, int ACost)
     : Target(ATarget), Cost(ACost) {}
    bool operator<(const TPath& Right)const
    {
        if(this->Cost  < 0) return false;
        if(Right.Cost < 0) return true;
        return this->Cost < Right.Cost;
    }
    bool operator>(const TPath& Right)const
    {
        return !((*this) < Right);
    }
};
class TVertex
{
    int FIndex;
    std::priority_queue<TPath, std::vector<TPath>, std::greater<TPath> > FList;
    int FDistance;

public:
    TVertex(int Index)
     : FIndex(Index), FDistance(INT_MAX)
    {}
    void Reserve(int Size)
    {
        // FList.reserve(Size);
    }
    void AddPath(const TPath& Path)
    {
        FList.push(Path);
    }
    void SortPath()
    {
        // std::sort(FList.begin(), FList.end(), Compare);
    }
    void PrintDistance(std::ostream& out)const
    {
        out << FIndex << " " << FDistance << std::endl;
    }
    int GetMinCostPath()const
    {
        if(FList.empty()) return INT_MAX;
        return FList.top().Cost + FDistance;
    }
    void PickupMinCostPath(int MinCost, std::list<TPath>& List)
    {
        while(FList.empty() == false && FList.top().Cost + FDistance == MinCost){
            List.push_back(TPath(FList.top().Target, FList.top().Cost + FDistance));
            FList.pop();
        }
    }
    bool SetDistance(int Distance)
    {
        if(FDistance < Distance) return false;
        FDistance = Distance;
        return true;
    }
};
class TGraph
{
    std::vector<TVertex*> FTable;
    std::set<TVertex*> FShortest;
    void Init(int n)
    {
        assert(n > 0);
        FTable.resize(n);
        for(int i = 0; i < n; ++i){
            FTable[i] = new TVertex(i);
        }
    }
    static bool CompareMinCost(const TVertex* Left, const TVertex* Right)
    {
        return Left->GetMinCostPath() < Right->GetMinCostPath();
    }
    void AddShortest(TVertex* Vertex, int Distance)
    {
        if(Vertex->SetDistance(Distance)){
            FShortest.insert(Vertex);
        }
    }
    std::list<TPath> PickupMinCostPath(int MinCost)
    {
        std::list<TPath> Result;
        for(std::set<TVertex*>::const_iterator It = FShortest.begin();
            It != FShortest.end(); ++It)
        {
            (*It)->PickupMinCostPath(MinCost, Result);
        }
        return Result;
    }
    void SetShortest(const std::list<TPath>& MinCostPathList)
    {
        for(std::list<TPath>::const_iterator It = MinCostPathList.begin();
            It != MinCostPathList.end(); ++It)
        {
            AddShortest(It->Target, It->Cost);
        }
    }
public:
    TGraph(int n)
    {
        Init(n);
    }
    void SetupVertex(std::istream& in)
    {
        int Index;
        in >> Index;
        assert(Index >= 0);
        assert(Index < FTable.size());
        int k;
        in >> k;
        FTable[Index]->Reserve(k);
        for(int i = 0; i < k; ++i){
            int v, c;
            in >> v >> c;
            FTable[Index]->AddPath(TPath(FTable[v], c));
        }
        FTable[Index]->SortPath();
    }
    void SearchShortest()
    {
        FTable[0]->SetDistance(0);
        FShortest.insert(FTable[0]);
        while(FShortest.size() != FTable.size()){
            int MinCost = (*std::min_element(FShortest.begin(), FShortest.end(), CompareMinCost))->GetMinCostPath();
            std::list<TPath> PathList = PickupMinCostPath(MinCost);
            SetShortest(PathList);
        }
    }
    void PrintDistance(std::ostream& out)
    {
        for(int i = 0; i < FTable.size(); ++i){
            FTable[i]->PrintDistance(out);
        }
    }
};

int main()
{
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    int n;
    std::cin >> n;
    TGraph Graph(n);
    for(int i = 0; i < n; ++i){
        Graph.SetupVertex(std::cin);
    }
    Graph.SearchShortest();
    Graph.PrintDistance(std::cout);
    return 0;
    
}

Measured memory_bytes: 12064