// Merge sort was taken from https://www.geeksforgeeks.org/c-program-for-merge-sort/

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

struct Pair
{
    int key;
    int value;
};

void merge(struct Pair* data, size_t left,
size_t center, size_t right) {
    struct Pair left_arr[center - left + 1];
    struct Pair right_arr[right - center];

    for (size_t i = 0; i < center - left + 1; ++i) {
        left_arr[i].key = data[left + i].key;
        left_arr[i].value = data[left + i].key;
    }
    for (size_t i = 0; i < right - center; ++i) {
        right_arr[i].key = data[center + i + 1].key;
        right_arr[i].value = data[center + i + 1].value;
    }

    size_t i = 0, j = 0;
    while (i < center - left + 1 && j < right - center) {
        if (left_arr[i].key <= right_arr[i].key) {
            data[center].key = left_arr[i].key;
            data[center].value = left_arr[i].value;
            ++i;
        } else {
            data[center].key = right_arr[j].key;
            data[center].value = right_arr[j].value;
            ++j;
        }
        ++center;
    }
    while (i < center - left + 1) {
        data[center].key = left_arr[i].key;
        data[center].value = left_arr[i].value;
        ++center;
        ++i;
    }
    while (j < right - center) {
        data[center].key = right_arr[j].key;
        data[center].value = right_arr[j].value;
        ++center;
        ++j;
    }
}

void merge_sort(struct Pair *data, size_t left, size_t right) {
    if (left < right) {
        size_t center = left + (right - left) / 2;
        merge_sort(data, left, center);
        merge_sort(data, center + 1, right);
        merge(data, left, center, right);
    }
}

void process(struct Pair *data, size_t size) {
    if (size == 0) return;
    merge_sort(data, 0, size - 1);
}

int main() {
    size_t n;
    struct Pair data[10];
    scanf("%lu", &n);
    for (size_t i = 0; i < n; ++i)
        scanf("%d %d", &data[i].key, &data[i].value);
    process(data, n);
    for (size_t i = 0; i < n; ++i)
        printf("key: %d; value: %d\n", data[i].key, data[i].value);
    return 0;
}