#include <bits/stdc++.h>
#define hb(x) (31 - __builtin_clz(x))
using namespace std;
const int mod = 1000000007, inv2 = 500000004;
inline int Mod(int x) { return x + ((x >> 31) & mod); }
inline int add(int x, int y) { return Mod(x + y - mod); }
inline int sub(int x, int y) { return Mod(x - y); }
inline int mul(int x, int y) { return 1ll * x * y % mod; }
const int maxn = 1 << 20;
char str[maxn + 5];
int pw2[maxn + 5], pw2i[maxn + 5];
int s0[maxn + 5];
int s1[2][25][maxn + 5], s2[2][25][maxn + 5];
void solve(int tp, int l, int r, int d) {
	if (l == r) return;
	int mid = (l + r) / 2;
	int *S1 = s1[tp][d], *S2 = s2[tp][d];
	S1[mid] = S2[mid] = 0;
	int sum = 0;
	if (str[mid] == '0' + tp) S1[mid] = pw2[mid], sum = pw2i[mid];
	for (int i = mid - 1; i >= l; i--) {
		S1[i] = S1[i + 1], S2[i] = S2[i + 1];
		if (str[i] == '0' + tp) {
			S1[i] = add(S1[i], pw2[i]);
			S2[i] = add(S2[i], mul(pw2[i], sum));
			sum = add(sum, pw2i[i]); 
		}
	}
	S1[mid + 1] = S2[mid + 1] = 0;
	sum = 0;
	if (str[mid + 1] == '0' + tp) S1[mid + 1] = pw2i[mid + 1], sum = pw2[mid + 1];
	for (int i = mid + 2; i <= r; i++) {
		S1[i] = S1[i - 1], S2[i] = S2[i - 1];
		if (str[i] == '0' + tp) {
			S1[i] = add(S1[i], pw2i[i]);
			S2[i] = add(S2[i], mul(pw2i[i], sum));
			sum = add(sum, pw2[i]);
		}
	}
	solve(tp, l, mid, d - 1), solve(tp, mid + 1, r, d - 1);
}
inline int query(int l, int r) {
	int d = hb((l - 1) ^ (r - 1));
	return add(add(add(s2[0][d][l], s2[0][d][r]), mul(s1[0][d][l], s1[0][d][r])), add(add(s2[1][d][l], s2[1][d][r]), mul(s1[1][d][l], s1[1][d][r])));
}
int main() {
	int n, q, sd;
	scanf("%d%d%d%s", &n, &q, &sd, str + 1);
	mt19937 rng(sd);
	pw2[0] = pw2i[0] = 1;
	for (int i = 1; i <= n; i++) pw2[i] = mul(pw2[i - 1], 2), pw2i[i] = mul(pw2i[i - 1], inv2);
	for (int i = 2; i <= n; i++) {
		s0[i] = s0[i - 1];
		if (str[i] == str[i - 1]) s0[i]++;
	}
	int l = 1, c = 0;
	while (l < n) l <<= 1, c++;
	solve(0, 1, l, c - 1), solve(1, 1, l, c - 1);
	long long ans = 0;
	for (int i = 1; i <= q; i++) {
		int l = rng() % n + 1, r = rng() % n + 1;
		if (l > r) swap(l, r);
		if (l == r) continue;
		int len = r - l + 1;
		int nw = sub(pw2[len - 1], len);
		nw = add(nw, s0[r] - s0[l]);
		nw = add(nw, mul(query(l, r), pw2[len - 1]));
		nw = mul(nw, inv2);
		ans ^= 1LL * i * nw;
	}
	printf("%lld", ans);
}