#include 
     
      using namespace std;#define INF 0x3f3f3f3f#define MAXN 1000010#define MAXM 5010inline int read(){    int x = 0,ff = 1;char ch = getchar();    while(!isdigit(ch))    {        if(ch == '-') ff = -1;        ch = getchar();    }    while(isdigit(ch))    {        x = (x << 1) + (x << 3) + (ch ^ 48);        ch = getchar();    }    return x * ff;}inline void write(int x){    if(x < 0) putchar('-'),x = -x;    if(x > 9) write(x / 10);    putchar(x % 10 + '0');}int a,ti = 0,cnt = 0,fa[MAXN],vis[MAXN],loop[MAXN];int lin[MAXN],tot = 0;struct edge{    int y,v,next;}e[MAXN];inline void add(int xx,int yy,int vv){    e[++tot].y = yy;    e[tot].v = vv;    e[tot].next = lin[xx];    lin[xx] = tot;}void get_loop(int x){    vis[x] = ++ti;    for(int i = lin[x],y;i;i = e[i].next)    {        if((y = e[i].y) == fa[x]) continue;        if(vis[y])        {            if(vis[y] < vis[x]) continue;            loop[++cnt] = y;            for(y = fa[y];y != fa[x];y = fa[y])            loop[++cnt] = y;            }        else fa[y] = x,get_loop(y);    }} int main(){    a = read();    for(int i = 1;i <= a;++i)    {        int y,v;        y = read(); v = read();        add(i,y,v);        add(y,i,v);    }    get_loop(1);    for(int i = 1;i <= cnt;++i)    write(loop[i]),putchar(' ');     return 0;}