#include <stdio.h>
#include <stdint.h>
#include <string.h>
#define MAX 10
typedef struct {
uint8_t buffer[MAX];
uint8_t head;
uint8_t count;
} stack1;
stack1 stack;
void process_stack(int n) {
// Your logic here
for (int i = 0; i < n; i++) {
char cmd[10];
scanf("%s", cmd);
if (strcmp(cmd, "push") == 0) {
int x;
scanf("%d", &x);
// xử lý push x
if (stack.head == MAX) printf("Stack Overflow\n");
else {
stack.buffer[stack.head] = x;
stack.head++;
stack.count++;
}
} else if (strcmp(cmd, "pop") == 0) {
// xử lý pop
if (stack.count == 0) {
printf("Stack Underflow\n");
} else {
printf("%d\n",stack.buffer[stack.head-1]);
stack.head--;
stack.count--;
}
}
}
}
int main() {
int n;
scanf("%d", &n);
getchar(); // Consume newline after number
process_stack(n);
return 0;
}