#include <stdio.h>
#include <stdint.h>
#include <string.h>
#define MAX 10
void process_stack(int n) {
// Your logic here
int buffer[MAX];
int head = 0;
int count = 0;
char cmd[20];
int x;
while (n--) {
fgets(cmd, sizeof(cmd), stdin);
if (strncmp(cmd, "push", 4) == 0) {
sscanf(cmd, "push %d", &x);
if (count == MAX) {
printf("Stack Overflow\n");
} else {
buffer[head] = x;
head = (head + 1) % MAX;
count++;
}
}
else if (strncmp(cmd, "pop", 3) == 0) {
if (count == 0) {
printf("Stack Underflow\n");
} else {
head = (head - 1 + MAX) % MAX;
printf("%d\n", buffer[head]);
count--;
}
}
}
}
int main() {
int n;
scanf("%d", &n);
getchar(); // Consume newline after number
process_stack(n);
return 0;
}