#include <cstdio>
#include <algorithm>
#include <cstring>
#define min(a,b) ((a)<(b)?(a):(b))
const int INF = 1027423549;int big = 250;
struct num {
	int v;
	num *next;
	num (int v,num *next): v(v),next(next) {};
}*d[21][21],*c[21][21];
typedef long long ll;
int a[30],T,n;
int f[21][21][251],b[21][21][251];
bool done[21][21][251],ok[21][21][251];
ll get(int l,int r) {
	ll o = 0;
	for (int i = l;i <= r;i++) {
		o = o * 10 + a[i];
		if (o > T) {
			o = big;
			return o;
		}
	}
	return o;
}
int main() {
	freopen("puzzle.in","r",stdin);
	freopen("puzzle.out","w",stdout);
	char ch;
	n = 0;
	while ((ch = getchar()) != '\n') 
		a[++n] = ch - '0';
	scanf("%d\n", &T);
	while (T != -1) {
		memset(f,61,sizeof(f));
		memset(b,61,sizeof(b));
		memset(done,0,sizeof(done));
		memset(ok,0,sizeof(ok));
		memset(d,0,sizeof(d));
		memset(c,0,sizeof(c));
		for (int len = 1;len <= n;len++) 
			for (int i = 1;i <= n - len + 1;i++) {
				int j = i + len - 1,tmp = get(i,j);
				f[i][j][tmp] = 0;
				if (!done[i][j][tmp]) {
					d[i][j] = new num(tmp,d[i][j]);
					done[i][j][tmp] = 1;
				}
				for (int k = i;k <= j - 1;k++) 
					for (num *p = d[i][k];p;p = p->next) 
						for (num *q = d[k + 1][j];q;q = q->next) {
							int u = p->v * q->v;
							if ((p->v == big || q->v == big) && u) u = big;
							if (u > T) u = big;
							f[i][j][u] = min(f[i][j][u],f[i][k][p->v] + f[k + 1][j][q->v] + 1);
							if (!done[i][j][u]) {
								done[i][j][u] = 1;
								d[i][j] = new num(u,d[i][j]);
							}
						}
			}
		for (int len = 1;len <= n;len++)
			for (int i = 1;i <= n - len + 1;i++) {
				int j = i + len - 1;
				for (num *p = d[i][j];p;p = p->next) {
					b[i][j][p->v] = min(b[i][j][p->v],f[i][j][p->v]);
					if (!ok[i][j][p->v]) {
						ok[i][j][p->v] = 1;
						c[i][j] = new num(p->v,c[i][j]);
					}
				}
				for (int k = i;k <= j - 1;k++)
					for (num *p = c[i][k];p;p = p->next)
						for (num *q = c[k + 1][j];q;q = q->next) {
							int u = p->v + q->v;
							if ((p->v == big || q->v == big) && u) u = big;
							if (u > T) u = big;
							b[i][j][u] = min(b[i][j][u],b[i][k][p->v] + b[k + 1][j][q->v] + 1);
							if (!done[i][j][u]) {
								done[i][j][u] = 1;
								c[i][j] = new num(u,c[i][j]);
							}
						}
			}
		int ans = b[1][n][T];
		if (ans == INF) ans = -1;
		printf("%d\n", ans);
		n = 0;
		while ((ch = getchar()) != '\n') 
			a[++n] = ch - '0';
		scanf("%d\n", &T);
	}
	return 0;
}