coada1

//Dragan Andrei Gabriel
//University of Bucharest

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

int v[1001], coada[50001], dim, m, x, indx;
char s[10];

int main()
{
    freopen("coada1.in", "r", stdin);
    freopen("coada1.out", "w", stdout);

    scanf("%d", &m);

    indx = 0, dim = 0;

    while (m--)
    {
        scanf("%s %d", s, &x);
        if (strcmp(s, "push") == 0)
        {
            if (v[x] > indx)
                indx = v[x], coada[++dim] = x, v[x] = dim;
                else
                    if (v[x] <= indx)
                        coada[++dim] = x, v[x] = dim;
        }else
        {
            if (v[x] > indx)
                printf("%d\n", v[x] - indx);
                else
                    printf("-1\n");
        }
    }

    return 0;
}