#include<bits/stdc++.h> using namespace std; #define IOS ios_base::sync_with_stdio(false);cin.tie(nullptr) #define INF 0x7fffffff #define inf 0x3f3f3f3f #define PII pair<int,int> #define endl '\n' #define int long long #define double long double #define mod 998244353 int read() {char act = 0;int f = 1, x= 0;while (act = getchar(), act < '0' && act != '-');if (act == '-') f = -1, act = getchar();x = act - '0';while (act = getchar(), act >= '0') x = x * 10 + act - '0';return x * f;} void solve(){ int n; cin>>n; //根据题意直接使用map即可 map<int,int>mp; for(int i=1;i<=n;i++){ int x,cnt; cin>>x>>cnt; mp[x]+=cnt; } for(auto i:mp){ cout<<i.first<<" "<<i.second<<endl; } } signed main() { IOS; int t=1; //cin>>t; while(t--){ solve(); } return 0; }