# include <bits/stdc++.h> using namespace std ; int n , m , a , b , s ; int d [101] [101] ; void floyd ( ) { for ( int k = 1 ; k <= n ; k ++ ) { for ( int i = 1 ; i <= n ; i ++ ) { for ( int j = 1 ; j <= n ; j ++ ) { if ( d [i] [k] != -1 && d [k] [j] != -1 ) { if ( d [i] [k] + d [k] [j] < d [i] [j] || d [i] [j] == -1 ) { d [i] [j] = d [i] [k] + d [k] [j] ; } } } } } } int main() { cin >> n >> m ; memset ( d , -1 , sizeof ( d ) ) ; for ( int i = 1 ; i <= m ; i ++ ) { cin >> a >> b >> s ; d [a] [b] = s ; } cin >> a >> b ; floyd ( ) ; cout << d [a] [b] + d [b] [a] << endl ; return 0 ; }