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#include <iostream>
#include <vector>
using namespace std;
vector<vector<int> > M;
int P[150][150];
bool visited[150];
vector<int> path;
bool dfs(int curx, int target){
    if(curx==target){
        if(path.size()==0) return true;
        bool flag=true;
        path.push_back(curx);
        for(int i=1;i<path.size();++i) 
        {
            if(P[path[i-1]][path[i]]){
                flag=false;
                break;
            }
            else P[path[i-1]][path[i]]=1;
        }
        path.pop_back();
        return flag;
    }
    else{
        path.push_back(curx);
        visited[curx]=true;
        bool flag=false;
        for(int i=0;i<M[curx].size();++i){
            int t=M[curx][i];
            if(!visited[t]) {
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