#include <cstdio>
#include <cassert>
#include <cctype>
#include <vector>
#include <algorithm>

using namespace std;
const int nMax = 50001;
vector< int > v[nMax];
vector< pair< int, int>> grad;

class inputParser {

    static const unsigned int buffSize = 1 << 17;
    unsigned int pozBuff;
    FILE *fin;
    unsigned char *buffer;


    void getChar( unsigned char &ch ) {
        if ( pozBuff == buffSize ) {
            pozBuff = 0;
            assert( fread( buffer, sizeof( char ), buffSize, fin ) );
        }
        ch = buffer[ pozBuff++ ];
    }


public:
    explicit inputParser( const char *fileName ) {
        fin = fopen( fileName, "r" );
        assert( fin != nullptr );
        buffer = new unsigned char[buffSize];
        pozBuff = buffSize;
    }


    inputParser( const inputParser &dummy ) = delete;

    inputParser &operator=( const inputParser &dummy ) = delete;


    template < class intType >
    inputParser &operator>>( intType &nr ) {
        int sgn( 1 );
        unsigned char ch;
        nr = 0;
        getChar( ch );
        while ( isdigit( ch ) == 0 && ch != '-' )
            getChar( ch );
        if ( ch == '-' ) {
            sgn = -1;
            getChar( ch );
        }
        while ( isdigit( ch ) != 0 ) {
            nr = nr * 10 + ch - '0';
            getChar( ch );
        }
        nr *= sgn;
        return *this;
    }


    inputParser &operator>>( char &ch ) {
        unsigned char ch2;
        do {
            getChar( ch2 );
        } while ( isgraph( ch2 ) == 0 );
        ch = static_cast<char>(ch2);
        return *this;
    }


    inputParser &operator>>( unsigned char &ch ) {
        getChar( ch );
        do {
            getChar( ch );
        } while ( isgraph( ch ) == 0 );
        return *this;
    }


    ~inputParser() {
        fclose( fin );
        delete[] buffer;
    }

};

int dfs( int nod ) {
    if ( v[ nod ].size() == 0 ) {
        grad[ nod ].first = -1;
        return -1;
    }
    else {
        for ( unsigned i = 0; i < v[ nod ].size(); i++ ) {
            grad[ nod ].first = min( grad[ nod ].first, dfs( v[ nod ][ i ] ) - 1 );
        }
        return grad[ nod ].first;
    }
}

int main() {
    int n, m;
    inputParser fin( "sortaret.in" );
    FILE *fout;
    fin >> n >> m;
    for ( int i = 0; i < m; i++ ) {
        int a, b;
        fin >> a >> b;
        v[ a ].push_back( b );
    }
    for ( int i = 0; i <= n; i++ )
        grad.push_back( { 0, i } );
    for ( int i = 0; i < n; i++ )
        if ( grad[ i ].first == 0 )
            dfs( grad[ i ].second );
    sort( grad.begin(), grad.end() );
    fout = fopen( "sortaret.out", "w" );
    for ( unsigned i = 0; i < grad.size(); i++ )
        if ( grad[ i ].second > 0 )
            fprintf( fout, "%d ", grad[ i ].second, grad[ i ].first );
    fclose( fout );

    return 0;
}