#include <cstdlib>
#include <fstream>
#define Nmax 19
#define Mmax 524288
#define oo 999999

/*
 *
 */
using namespace std;
int d[Nmax], dd[Nmax];
int G[Nmax][Nmax], C[Nmax][Nmax], CC[Mmax][Nmax];
int main( void )
{
    int N, M, x, y, x2, y2, z, s, till;
    ifstream in( "hamilton.in" );
    ofstream out( "hamilton.out" );
    in>>N>>M;
    for( x=0; x < N; ++x )
        for( y=0; y < N; ++y )
            C[x][y]=oo;
    for( ; M; --M )
    {
        in>>x>>y;
        in>>C[x][y];
        G[y][++G[y][0]]=x;
        ++d[x]; ++dd[y];
    }
    for( x=0; x < N; ++x )
        if( 0 == d[x]*dd[x] )
        {
            out<<"-1\n";
            return EXIT_SUCCESS;
        }
    till=1<<N;
    for( x=0; x < till; ++x )
        for( y=0; y < N; ++y )
            CC[x][y]=oo;
    CC[1][0]=0;
    for( x=0; x < till; ++x )
        for( y=0, y2=1; y < N; ++y, y2<<=1 )
            if( x & y2 )
                for( x2=x^y2, z=1; z <= G[y][0]; ++z )
                    if( x & (1<<G[y][z]) )
                        CC[x][y]=min( CC[x][y], CC[x2][G[y][z]]+C[G[y][z]][y] );
    for( s=oo, till-=1, x=1; x <= G[0][0]; ++x )
        s=min( s, CC[till][G[0][x]]+C[G[0][x]][0] );
    if( oo == s )
        out<<"-1\n";
    else out<<s<<'\n';
    return EXIT_SUCCESS;
}