#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <queue>
#define ll long long
#define lf double
#define _1 first
#define _2 second
#define _mp make_pair
#define _pb push_back
#define inf 22222222222222ll
#define MAX_N 522222

using namespace std;

ll read(){ll x = 0;char c = 0, v = 0;do{c = getchar();if(c == '-')v = 1;} while(c < '0' || c > '9');do{x = (x << 3) + (x << 1) + c - '0';c = getchar();} while(c >= '0' && c <= '9');if(v)return -x;return x;}

int n, m;

struct node
{
    char c;
    int len;
};

char s[MAX_N], t[MAX_N];
vector<pair<int, int> > opps;
node a[MAX_N], b[MAX_N];
node tmpx[MAX_N], tmpy[MAX_N];

void input()
{
    scanf("%s", s);
    scanf("%s", t);
    int sl = strlen(s), tl = strlen(t);
    n = m = 0;
    for(int i = sl - 1; ~i; i--)
        if(!n || s[i] != a[n - 1].c)
            a[n++] = (node){s[i], 1};
        else
            a[n - 1].len++;
    for(int i = tl - 1; ~i; i--)
        if(!m || t[i] != b[m - 1].c)
            b[m++] = (node){t[i], 1};
        else
            b[m - 1].len++;
}

void opt(int x, int y)
{
    int sumx = 0, sumy = 0;
    for(int i = n - 1; i >= n - x; i--)
        sumx += a[i].len, tmpx[i - (n - x)] = a[i];
    for(int i = m - 1; i >= m - y; i--)
        sumy += b[i].len, tmpy[i - (m - y)] = b[i];
    opps._pb(_mp(sumx, sumy));
    n -= x, m -= y;
    if(n && y && tmpy[0].c == a[n - 1].c)
        a[n - 1].len += tmpy[0].len;
    else if(y)
        a[n++] = tmpy[0];
    for(int i = 1; i <= y - 1; i++)
        a[n++] = tmpy[i];
    if(m && x && tmpx[0].c == b[m - 1].c)
        b[m - 1].len += tmpx[0].len;
    else if(x)
        b[m++] = tmpx[0];
    for(int i = 1; i <= x - 1; i++)
        b[m++] = tmpx[i];
    /*printf("opt %d %d %d %d\n", n, m, x, y);
    for(int i = 0; i < n; i++)
        printf("%c %d\n", a[i].c, a[i].len);
    printf("\n");
    for(int i = 0; i < m; i++)
        printf("%c %d\n", b[i].c, b[i].len);*/
}

void mree()
{
    while(n >= 4 && m >= 4)
        if(a[n - 1].c == b[m - 1].c)
            opt(1, 2), opt(2, 1);
        else
            opt(1, 1);
}

void parr()
{
    if(n >= 3 && m == 1)
    {
        int pos = n, val = n - 1;
        for(int i = 1; i < n; i++)
        {
            int d = abs(i - (n - i));
            if(d < val)
                val = d, pos = i;
        }
        if(pos != n)
            if(a[pos].c == b[0].c)
                opt(n - pos, 0);
            else
                opt(n - pos, 1);
        return;
    }
    if(m >= 3 && n == 1)
    {
        /*for(int i = 0; i < n; i++)
            printf("%c %d\n", a[i].c, a[i].len);
        printf("\n");
        for(int i = 0; i < m; i++)
            printf("%c %d\n", b[i].c, b[i].len);*/
        int pos = m, val = m - 1;
        for(int i = 1; i < m; i++)
        {
            //printf("%d\n", i);
            int d = abs(i - (m - i));
            if(d < val)
                val = d, pos = i;
        }
        if(pos != m)
            if(b[pos].c == a[0].c)
                opt(0, m - pos);
            else
                opt(1, m - pos);
        return;
    }
    int pi = n, pj = m, val = n + m + 1;
    for(int i = 1; i < n; i++)
        for(int j = 1; j < m; j++)
            if(a[i].c == b[j - 1].c && a[i - 1].c == b[j].c)
            {
                int d = abs((i + (m - j) - 1) - (j + (n - i) - 1));
                if(d < val)
                    val = d, pi = i, pj = j;
            }
    if(pi != n && pj != m)
        opt(n - pi, m - pj);
    return;
}

void bass()
{
    //printf("%d %d\n", n, m);
    if(n == 1 && m == 1)
        return;
    if(a[n - 1].c != b[m - 1].c)
    {
        while(!(n == 1 && m == 1) && a[n - 1].c != b[m - 1].c)
            opt(1, 1);
        return;
    }
    if(n == 1)
        opt(0, 1), bass();
    else if(m == 1)
        opt(1, 0), bass();
    else if(n > m)
        opt(2, 1), bass();
    else
        opt(1, 2), bass();
}

void output()
{
    printf("%d\n", (int)opps.size());
    for(auto i: opps)
        printf("%d %d\n", i._1, i._2);
}

int main()
{
    input(), mree(), parr(), mree(), bass(), output();
    return 0;
}