#include <iostream>
#include <algorithm>
#include <vector>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 1e6 + 10;

int n, m, a[MAXN], pos[MAXN];
char s[MAXN];
int pre[MAXN], suf[MAXN];
vector < pair <int, int> > res;

inline void Delete(int pos, int len)
{
    if (len & 1) res.emplace_back(pos, 3), len -= 3;
    for (int i = 1; i <= len / 2; i++)
        res.emplace_back(pos, 2);
}
inline void Solve(int l, int r)
{
    int mid = l + r >> 1, lpos = mid, rpos = mid;
    while (a[lpos] == 1) lpos--;
    while (a[rpos] == 1) rpos++;
    int p = lpos + 1;
    for (int i = 1; i <= rpos - mid; i++)
    {
        Delete(pos[lpos], a[lpos]);
        a[--lpos]++, p++;
    }
    pos[p] = pos[lpos] + a[lpos];
    for (int i = p + 1; i <= r; i++) pos[i] = pos[i - 1] + a[i - 1];
    Delete(pos[rpos], a[rpos]);
    int lp = rpos - 1, rp = rpos + 1;
    while (rp <= r)
    {
        if (lp == p - 1) lp = lpos;
        Delete(pos[lp], a[lp] + a[rp]);
        lp--, rp++;
    }
}
inline void Print()
{
    cout << res.size() << '\n';
    for (auto x : res) cout << x.first << ' ' << x.second << '\n';
}

int main()
{
    // freopen("C.in", "r", stdin);
    // freopen("C.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(n), Read(s + 1);
    pos[0] = 1;
    for (int i = 1, cnt = 0; i <= n + 1; i++)
    {
        if (i != 1 && s[i] != s[i - 1]) a[++m] = cnt, pos[m] = pos[m - 1] + a[m - 1], cnt = 1;
        else cnt++;
    }
    for (int i = 1; i <= m; i++) pre[i] = (a[i] == 1 ? pre[i - 1] + 1 : 0);
    for (int i = m; i >= 1; i--) suf[i] = (a[i] == 1 ? suf[i + 1] + 1 : 0);
    if (m & 1)
    {
        int mid = m + 1 >> 1;
        if (pre[mid] + suf[mid] >= mid) cout << "-1\n";
        else Solve(1, m), Print();
        return 0;
    }
    for (int i = 1; i <= m; i += 2)
    {
        int lmid = i + 1 >> 1, rmid = i + m + 1 >> 1;
        if (pre[lmid] + suf[lmid] < lmid && pre[rmid] + suf[rmid] < rmid)
        {
            Solve(i + 1, m), Solve(1, i), Print();
            return 0;
        }
    }
    cout << "-1\n";
    return 0;
}