#include <stdio.h>
#include <stdbool.h>
int is_alternating_pattern(int *mem, int k) {
int i=0;
int precCarac;
bool patFound=false;
while(i<k){
if(patFound){
if(*(mem+i)^1 == precCarac) precCarac^=1;
else return 0;
}
if(!patFound){
if(*(mem+i)==1 || *(mem+i)==0){
precCarac = *(mem+i);
patFound = true;
}
}
i++;
}
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;
}