#include #define LL long long #define PII pair #define PLI pair #define lson o<<1,l,mid #define rson o<<1|1,mid+1,r #define lowbit(x) (x&(-x)) using namespace std; const int maxn=100010,inf=1e9+10; int T,n,m,k,ans[maxn]; int main(){ #ifdef OJ freopen("data.in","r",stdin); freopen("data.out","w",stdout); #endif scanf("%d",&T); while(T--){ scanf("%d %d %d",&n,&m,&k); for(int i=1;i<=n;i++){ ans[i]=inf; } ans[k]=0; for(int i=1;i<=m;i++){ int u,v; scanf("%d %d",&u,&v); if(ans[u]!=inf || ans[v]!=inf){ if(ans[u]