#include <stdio.h>

void chmin(int *a, int b)
{
	if (*a > b) *a = b;
}

int main()
{
	int i, N, Q, l[300000], r[300000];
	char S[300000];
	scanf("%d %d", &N, &Q);
	scanf("%s", &(S[1]));
	for (i = 1; i <= Q; i++) scanf("%d %d", &(l[i]), &(r[i]));
	
	int j, k, cand[100][3];
	for (j = 104, k = 0; j < 1000; j += 8) {
		if (j % 10 == 0 || j / 10 % 10 == 0) continue;
		cand[++k][0] = j / 100;
		cand[k][1] = j / 10 % 10;
		cand[k][2] = j % 10;
	}
	
	int last[300000][10], x[3], ans, tmp;
	for (j = 1; j <= 9; j++) last[0][j] = 0;
	for (i = 1; i <= N; i++) {
		for (j = 1; j <= 9; j++) last[i][j] = last[i-1][j];
		last[i][S[i] - '0'] = i;
	}
	for (i = 1; i <= Q; i++) {
		if (l[i] == r[i]) {
			if (S[l[i]] == '8') printf("0\n");
			else printf("-1\n");
		} else if (l[i] == r[i] - 1) {
			tmp = (S[l[i]] - '0') * 10 + S[r[i]] - '0';
			if (tmp % 8 == 0) printf("0\n");
			else {
				tmp = (S[r[i]] - '0') * 10 + S[l[i]] - '0';
				if (tmp % 8 == 0) printf("1\n");
				else printf("-1\n");
			}
		} else {
			for (j = 1, ans = N * 3; j <= k; j++) {
				x[2] = last[r[i]][cand[j][2]];
				if (x[2] < l[i]) continue;
				
				if (cand[j][1] == cand[j][2]) x[1] = last[x[2]-1][cand[j][1]];
				else x[1] = last[r[i]][cand[j][1]];
				if (x[1] < l[i]) continue;

				if (cand[j][0] == cand[j][1]) x[0] = last[x[1]-1][cand[j][0]];
				else if (cand[j][0] == cand[j][2]) x[0] = last[x[2]-1][cand[j][0]];
				else x[0] = last[r[i]][cand[j][0]];
				if (x[0] < l[i]) continue;
				
				x[0] = r[i] - x[0];
				x[1] = r[i] - x[1];
				x[2] = r[i] - x[2];
				
				tmp = x[2] + x[1] - 1 + x[0] - 2;
				if (x[1] < x[2]) tmp++;
				if (x[0] < x[1]) tmp++;
				if (x[0] < x[2]) tmp++;
				chmin(&ans, tmp);
				// printf("%d %d %d: %d %d %d: %d\n", cand[j][0], cand[j][1], cand[j][2], x[0], x[1], x[2], tmp);
			}
			if (ans == N * 3) printf("-1\n");
			else printf("%d\n", ans);
		}
	}
	fflush(stdout);
	return 0;
}