#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>



int  check(int i,int32_t *mas,int len)
{
    if(2*i+1>len) return 2;
    if(2*i+2>len)
    {
        if(mas[2*i+1]>mas[i])return 1;
        if(mas[2*i+1]<mas[i])return -1;
       if(mas[2*i+1]==mas[i])return 2;
   }
   int right=check(2i+2,mas,len);
   int left =check(2i+1,mas,len);
   if(right==0 || left==0)return 0;
   if(mas[2*i+1]==mas[i] && mas[2*i+2]==mas[i] && (left==2 && right==2))return 2;
   if(mas[2*i+1]>=mas[i] && mas[2*i+2]>=mas[i] && (left==1||left==2) && (right==1|| right==2))
       return 1;
    if(mas[2*i+1]<=mas[i] && mas[2*i+2]<=mas[i] && (left==-1||left==2) && (right==-1|| right==2))
       return -1;
   else return 0;



}

int main(void) {

   int32_t *mas =(int32_t*)malloc(1049576* sizeof(int));

   FILE *input =fopen("input.bin","rb");
   FILE *output = fopen("output.bin","wb");
   int len=0;
   while(!fread(&mas[len], 1 , sizeof(int32_t), input)){
   len++;
   }
   int ans=check(0,mas, len);
   if(ans==2)ans=1;
   fwrite(ans, 1,sizeof(int32_t),output);
fclose(output);
fclose(input);
   return 0;
}