#include <iostream>
#include <vector>
#include <fstream>


using namespace std;

//void Merch( vector<int> &first, vector<int> &second){
//        int i = 0;
//        int j = 0;
//        vector<int> SortArr( first.size() + second.size() );
//
//        while( i < first.size() && j < second.size() ) {
//            if( first[i] > second[j] ) {
//                SortArr[i+j] = second[j];
//                j++;
//            } else {
//                SortArr[i+j] = first[i];
//                i++;
//            }
//        }
//
//    if( i == first.size() ) {
//        for( ; j < second.size(); j++ ) {
//            SortArr[i+j] = second[j];
//        }
//    } else {
//        for( ; i < first.size(); i++ ) {
//            SortArr[i+j] = first[i];
//        }
//    }
//}

void SiftDown( vector<int> &arr, int i, int last ){
    int j = 0;
    int left = 0;
    int right = 0;

    while( i < last ) {
        j = i;
        left = (2 * i) + 1;
        right = left + 1;

    if( left < last && arr[j] < arr[left] ) {
        j = left;
    }

    if( right < last && arr[j] < arr[right] ) {
        j = right;
    }

    if( j == i ) return ;
    swap( arr[j], arr[i] );
    i = j;
    }
}

void BuildHeap( vector<int> &arr, int right ) {
    for( int i = right/2 - 1 ; i >= 0; i-- ) {
        SiftDown( arr, i, right );
    }
}

void HeapSort(  vector<int> &arr, int right ){
    int last = right;
    BuildHeap( arr, right );

    while( last > 0 ) {
        swap( arr[0], arr[last] );
        SiftDown( arr, 0, last );
        last--;
    }
}

int med (vector<int> &arr, int right, int left)
{
    int middle = (right+left)/2;
    if (arr[right] > arr[middle]) {
        if (arr[left] > arr[right]){
            return right;
        }
        return (arr[middle] > arr[left]) ? middle : left;
    }
    if (arr[left] > arr[middle]){
        return middle;
    }
    return (arr[right] > arr[left]) ? right : left;
}

void InsertionSort( vector<int> &arr, int left, int right ){
        for( int i = left + 1; i < right; ++i ) {
            int tmp = arr[i];
            int j = i - 1;
            for( ; j >= left && tmp < arr[j]; --j ) {
                arr[j + 1] = arr[j];
            }
            arr[j + 1] = tmp;
        }
}

int Partition ( vector<int> &arr, int left, int right) {
    int i = left;
    int j = right - 1;
    int median = med(arr, right, left);
    int pivot = arr[median];

    while ( i <= j ) {
        for ( ; i <= right && ( arr[i] < pivot ); i++ ) {
        }
        for ( ; j >= left && ( arr[j] >= pivot ); j-- ) {
        }
        if ( i < j ) {
            swap ( arr[i++], arr[j--] );
        }
    }
    swap ( arr[i], arr[median] );

    return i;
}

void QSort ( vector<int> &arr, int left, int right ) {
    if ( right - left >= 11 ) {
    int part = Partition(arr, left, right);
    QSort(arr, left, part - 1);
    QSort ( arr, part + 1, right );
    } else {
        InsertionSort(arr, left, right + 1);
    }
}

int main() {
    int n = 0;
    int tmp = 0;
    vector<int> arr(0);
    ifstream text("input.txt");

    while (!text.eof()){
        text >> tmp;
        arr.push_back(tmp);
    }
    arr.pop_back();

    text.close();
    n = arr.size();
    QSort ( arr, 0, n - 1 );
    for ( int i = 9; i < n; i=i+10 ) {
       printf("%d", arr[i]);

    }

    return 0;
}