#include <stdio.h>
 
#define BLACK 0
#define WHITE 1
 
int n;
int x[10], y[10];
int slip[10];
 
int solve(int person_id)
{
    if (person_id > 0)
    {
        slip[person_id] = BLACK;
        if (solve(person_id - 1))
            return 1;
 
        slip[person_id] = WHITE;
        return solve(person_id - 1);
    }
    else
    {
        int n_black = 0, n_white = 0;
        for (int i = 1; i <= n; ++i)
        {
            if (slip[i] == BLACK)
                n_black++;
            else
                n_white++;
        }
 
        for (int i = 1; i <= n; ++i)
        {
            if (slip[i] == WHITE)
            {
                if (!(x[i] == n_white - 1 && y[i] == n_black))
                    return 0;
            }
            else
            {
                if (x[i] == n_white && y[i] == n_black - 1)
                    return 0;
            }
        }
 
        return 1;
    }
}
 
int main()
{
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i)
        scanf("%d %d", &x[i], &y[i]);
 
    if (solve(n))
    {
        int n_black = 0, n_white = 0;
        for (int i = 1; i <= n; ++i)
        {
            if (slip[i] == BLACK)
                n_black++;
            else
                n_white++;
        }
 
        if (n_black == n)
            printf("0");
        else
        {
            for (int i = 1; i <= n; ++i)
            {
                if (slip[i] == WHITE)
                    printf("%d", i);
            }
        }
    }
    else
        printf("NoSolution.");
 
    return 0;
}