#include <bits/stdc++.h>
using namespace std;

bool my(pair <const int, int> a, pair <const int, int> b) {
	if (a.second < b.second) {
		return false;
	}
	
	return true;
}

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

	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);

	int n = 8;
	vector <int> a = {4, 2, 3, 4, 5, 6, 7, 1};
	
	unordered_map <int, int> vl;
		
	for (int i : a) {
		if (!vl[i]) {
			vl[i] = 1;
		} else {
			vl[i] += 1;
		}
		
	}
	
	// sort(vl.begin(), vl.end(), my);
	
	
	for (auto i : vl) cout << i.first << ": " << i.second << "\n";
	return 0;

	return 0;
}