/*==========================================================================

# Last modified: 2016-03-07 14:07

# Filename: uva10806.cpp

# Description:

==========================================================================*/

#define me AcrossTheSky

#include <cstdio>

#include <cmath>

#include <ctime>

#include <string>

#include <cstring>

#include <cstdlib>

#include <iostream>

#include <algorithm> 

#include <set>

#include <map>

#include <stack>

#include <queue>

#include <vector> 

#define lowbit(x) (x)&(-x)

#define FOR(i,a,b) for((i)=(a);(i)<=(b);(i)++)

#define FORP(i,a,b) for(int i=(a);i<=(b);i++)

#define FORM(i,a,b) for(int i=(a);i>=(b);i--)

#define ls(a,b) (((a)+(b)) << 1)

#define rs(a,b) (((a)+(b)) >> 1)

#define getlc(a) ch[(a)][0]

#define getrc(a) ch[(a)][1] 

#define maxn 1000

#define maxm 100000

#define pi 3.1415926535898

#define _e 2.718281828459

#define INF 1070000000

using namespace std;

typedef long long ll;

typedef unsigned long long ull; 

template<class T> inline

void read(T& num) {

    bool start=false,neg=false;

    char c;

    num=0;

    while((c=getchar())!=EOF) {

        if(c=='-') start=neg=true;

        else if(c>='0' && c<='9') {

            start=true;

            num=num*10+c-'0';

        } else if(start) break;

    }

    if(neg) num=-num;

}

/*==================split line==================*/

struct Edge{

	int from,to,w,c;

}e[maxm];

int sume,flow,ans,n,m;

int d[maxn],first[maxn],next[maxm],from[maxn];

bool inq[maxn];

void addedge(int x,int y,int cap,int cost){

	sume++; e[sume].from=x; e[sume].to=y; e[sume].w=cap; e[sume].c=cost;

	next[sume]=first[x]; first[x]=sume;

	sume++; e[sume].from=y; e[sume].to=x; e[sume].w=0; e[sume].c=-cost;

	next[sume]=first[y]; first[y]=sume;

}

bool spfa(){

	queue<int> q;

	FORP(i,0,n) d[i]=INF;

	memset(inq,false,sizeof(inq));

	memset(from,0,sizeof(from));

	q.push(0); d[0]=0; inq[0]=true;

	while(!q.empty()){

		int now=q.front(); q.pop(); inq[now]=false;

		for(int i=first[now];i!=-1;i=next[i])

		if (e[i].w && d[now]+e[i].c<d[e[i].to]) {

			d[e[i].to]=d[now]+e[i].c;

			from[e[i].to]=i;

			//q.push(e[i].to);

			if (!inq[e[i].to]){

				inq[e[i].to]=true;

				q.push(e[i].to);

			}

		}

	}

	if (d[n]==INF) return false;

	return true;

}

void mincost(){

	int x=INF,i=from[n];

	while (i) {

		x=min(e[i].w,x); i=from[e[i].from];

	}

	flow+=x;

	i=from[n];

	while (i){

		e[i].w-=x;

		e[i^1].w+=x;

		//ans+=(x*e[i].c);

		i=from[e[i].from];

	}

	ans+=d[n]*x;

}

void reset(){

	sume=1; flow=0; ans=0;

	memset(e,0,sizeof(e));

	FORP(i,0,maxn) first[i]=-1;

	memset(next,0,sizeof(next));

}

int main(){

	while (scanf("%d",&n)!=EOF){

		reset();

		 if (n==0) return 0;

		 read(m);

		 FORP(i,1,m) {

		 	int x,y,w; read(x); read(y); read(w);

			addedge(x,y,1,w);

			addedge(y,x,1,w);

		 }

		 addedge(0,1,2,0);

		 addedge(n,n+1,2,0);

		 n++;

		 while (spfa()) mincost();

		 if (flow<2) printf("Back to jail\n");

		 else printf("%d\n",ans);

	}

}