Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	q := io.NextInt()
	for i := 0; i < q; i++ {
		io.Println(solve(io.NextInt()))
	}
}

func solve(n int) int {
	f := func(n int) int {
		max := 0
		for i := 10; ; i *= 10 {
			a := n / i
			b := n % i
			if a == 0 {
				break
			}
			max = intMax(a*b, max)
		}
		return max
	}

	cnt := 0
	for {
		if n < 10 {
			break
		}
		n = f(n)
		cnt++
	}

	return cnt
}

func intMax(a, b int) int {
	if a < b {
		return b
	}
	return a
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include "bits/stdc++.h"
#define REP(i,a,b) for(i=a;i<b;++i)
#define rep(i,n) REP(i,0,n)
#define ll long long
#define ull unsigned ll
typedef long double ld;
#define ALL(a) (a).begin(),(a).end()
#define ifnot(a) if(not a)
#define dump(x)  cerr << #x << " = " << (x) << endl
using namespace std;

void reader(int &a) { scanf("%d", &a); }
void reader(double &a) { scanf("%lf", &a); }
void reader(char a[]) { scanf("%s", a); }
void reader(char &a) { scanf(" %c", &a); }
void reader(ll &a) { scanf("%lld", &a); }
void reader(ull &a) { scanf("%llu", &a); }
// void reader(string& a){cin >> a;};
template<class T, class U> void reader(T& t, U& u) { reader(t); reader(u); }
template<class T, class U, class V> void reader(T& t, U& u, V& v) { reader(t); reader(u); reader(v); }

void writer(const int a, char c) { printf("%d", a); putchar(c); }
void writer(const ll a, char c) { printf("%lld", a); putchar(c); }
void writer(const ull a, char c) { printf("%llu", a); putchar(c); }
void writer(const double a, char c) { printf("%.20lf", a); putchar(c); }
void writer(const char a[]) { printf("%s", a); };
void writer(const char a[], char c) { printf("%s", a); putchar(c); };
void writer(const char a, char c) { putchar(a); putchar(c); };
template<class T> void writerLn(T t) { writer(t, '\n'); }
template<class T, class U> void writerLn(T t, U u) { writer(t, ' '); writer(u, '\n'); }
template<class T, class U, class V> void writerLn(T t, U u, V v) { writer(t, ' '); writer(u, ' '); writer(v, '\n'); }
template<class T> void writerArr(T x[], int n) { int i; if (!n) { putchar('\n'); return; }rep(i, n - 1) writer(x[i], ' '); writer(x[n - 1], '\n'); }
template<class T> void writerVec(vector<T> x) { int n = x.size(); int i; if (!n) { putchar('\n'); return; }rep(i, n - 1) writer(x[i], ' '); writer(x[n - 1], '\n'); }

vector<string> split(const string &str, char sep) { vector<string> v; stringstream ss(str); string buffer; while (getline(ss, buffer, sep)) { v.push_back(buffer); }return v; }
// #define int ll
bool test = 1;
int dx[] = { 0,1,0,-1 };
int dy[] = { 1,0,-1,0 };
#define MAX 300000
//.....................
ull mod = (int)1e9 + 7;

signed main(void)
{
	int i, j, k;
	int q;
	cin >> q;
	rep(i, q) {
		string s;
		cin >> s;
		int n = stoi(s);
		int cnt = 0;
		while (n > 9) {
			cnt++;
			int next_n = INT_MIN;
			REP(j, 1, s.size()) {
				int a1 = stoi(s.substr(0, j));
				int a2 = stoi(s.substr(j));
				if (a1*a2 > next_n) {
					next_n = a1*a2;
				}
			}
			n = next_n;
			s = to_string(n);
		}
		cout << cnt << endl;
	}
	return 0;
}

C++: #include <algorithm>
#include <iostream>
#include <vector>

using namespace std;

typedef vector<int> VI;

const int SIZE = 1000001;

VI memo( SIZE, -2 );

int dfs ( int num )
{
	if ( memo[num] != -2 ) {
		return memo[num];
	}
	if ( num < 10 ) {
		return memo[num] = 0;
	}
	int m = 10,
		next = 0,
		res = -1;
	memo[num] = -1;
	while ( num >= m ) {
		next = max( next, ( num / m ) * ( num % m ) );
		m *= 10;
	}
	res = dfs( next );
	if ( res != -1 ) {
		++res;
	}
	return memo[num] = res;
}

int main ( void )
{
	int q;
	while ( cin >> q ) {
		for ( int i = 0; i < q; ++i ) {
			int n;
			cin >> n;

			cout << dfs( n ) << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <ctime>
using namespace std;

#define rep(i,a,n) for(int i=a; i<n; i++)
#define repq(i,a,n) for(int i=a; i<=n; i++)
#define repr(i,a,n) for(int i=a; i>=n; i--)
#define pb(a) push_back(a)
#define fr first
#define sc second
#define INF 999999999

#define X real()
#define Y imag()
#define EPS (1e-10)
#define EQ(a,b) (abs((a) - (b)) < EPS)
#define EQV(a,b) ( EQ((a).X, (b).X) && EQ((a).Y, (b).Y) )
#define LE(n, m) ((n) < (m) + EPS)
#define GE(n, m) ((n) + EPS > (m))

typedef vector<int> VI;
typedef vector<VI> MAT;
typedef pair<int, int> pii;
typedef long long int ll;

typedef complex<double> P;
typedef pair<P, P> L;
typedef pair<P, double> C;

int const MOD = 1000000007;

int main() {
    int q; cin >> q;
    rep(i,0,q) {
        string s; cin >> s;
        int cnt = 0;
        while(1) {
            // cout << s << endl;
            if(s.length() == 1) break;
            else {
                int ma = 0;
                repq(i,1,s.length()) {
                    string s1 = s.substr(0,i);
                    string s2 = s.substr(i,s.length() - i);
                    ma = max(ma, atoi(s1.c_str()) * atoi(s2.c_str()));
                }
                s = to_string(ma);
                cnt++;
            }
        }
        cout << cnt << endl;
    }
    return 0;
}