#include<stdio.h>
int size,arr[];
 int top=-1;

int isFull(){
    if(top==size-1)
        return 1;
    else
        return 0;
}
int push(int num){
    if(isFull())
        printf("Invalid input");
    else
        arr[++top]=num;
}
void traverse(){
    int i;
    for(i=0;i<size;i++)
        printf("%d",arr[i]);
}
int main(){
    int size,in;
    scanf("%d",&size);
    for(in=0;in<size;in++){
        scanf("%d",&in);
        push(in);
        
    }
    traverse();
    return 0;
}