#include <stdio.h>
int is_alternating_pattern(int *mem, int k) {
// Write your pointer logic here
for (int i=0;i<k/2;i++){
if (*(mem+i) == *(mem+k-1-i) && (k/2 -1 )!=i)
return 0;
}
return 1;
}
int main() {
int n, k, arr[100];
scanf("%d %d", &n, &k);
for (int i = 0; i < n; i++) {
scanf("%d", &arr[i]);
}
int res = is_alternating_pattern(arr, k);
printf("%d", res);
return 0;
}