#include <stdio.h>
int is_alternating_pattern(int *mem, int k) {
// Write your pointer logic here
int* even = mem;
int* odd = mem + 1;
for(int i=0; i<k; i++)
{
if(i%2 == 0) //even
{
if(*even != *(mem + i))
{
return 0;
}
}
else //odd
{
if(*odd != *(mem + 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;
}