#include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<algorithm> using namespace std; const int MAXN=400; const int INF=0x7fffffff; int N,M,S; int a[MAXN][MAXN],dis[MAXN]; bool visit[MAXN],d[MAXN]; int StoerWagner(int N) { int p=N,ans=INF,Max,t,s,k,i; memset(d,0,sizeof(d)); while (--p>0) { memset(visit,0,sizeof(visit)); memset(dis,0,sizeof(dis)); i=1; while (d[i]) i++; visit[i]=1; for (int j=1;j<=N;j++) if (!d[j] && !visit[j]) dis[j]=a[i][j]; t=s=i; for (;i<=N;i++) { Max=0; for (int j=1;j<=N;j++) if (!d[j] && !visit[j] && Max<dis[j]) Max=dis[k=j]; if (!Max) break; visit[k]=1; for (int j=1;j<=N;j++) if (!d[j] && !visit[j]) dis[j]+=a[k][j]; s=t; t=k; } if (ans>dis[t]) ans=dis[t]; d[t]=1; for (int j=1;j<=N;j++) if (!d[j]) { a[s][j]+=a[t][j]; a[j][s]+=a[j][t]; } } return ans; } int main() { while (1) { scanf("%d%d%d",&N,&M,&S); if (!N && !M && !S) break;///N 点数,M 边数,S起点 memset(a,0,sizeof(a)); for (int i=1;i<=M;i++) { int x,y,d; scanf("%d%d%d",&x,&y,&d); a[x][y]+=d; a[y][x]+=d; } printf("%d ",StoerWagner(N)); } return 0; }