local read, p = io.read, print;
local concat = table.concat;
local function shortest_path(n, i, j, i2, j2, t)
    if (i2 - i) % 2 ~= 0 or ((j2 - j) % 2 == 0 and (i2 - i) % 4 == 2) then
        return nil;
    end
    if i > i2 and j > j2 then
        t[#t + 1] = 'UL';
        return shortest_path(n, i-2, j-1, i2, j2, t);
    elseif i > i2 and j < j2 then
        t[#t + 1] = 'UR';
        return shortest_path(n, i-2, j+1, i2, j2, t);
    elseif i == i2 and j < j2 then
        t[#t + 1] = 'R';
        return shortest_path(n, i, j+2, i2, j2, t);
    elseif i < i2 and j < j2 then
        t[#t + 1] = 'LR';
        return shortest_path(n, i+2, j+1, i2, j2, t);
    elseif i < i2 and j > j2 then
        t[#t + 1] = 'LL';
        return shortest_path(n, i+2, j-1, i2, j2, t);
    elseif i == i2 and j > j2 then
        t[#t + 1] = 'L';
        return shortest_path(n, i, j-2, i2, j2, t);
    elseif i == i2 and j == j2 then
        return t;
    elseif i < i2 and j == j2 then
        if j < n-2 then
            t[#t + 1] = 'LR';
            return shortest_path(n, i+2, j+1, i2, j2, t);
        else
            t[#t + 1] = 'LL';
            return shortest_path(n, i+2, j-1, i2, j2, t);
        end
    elseif i > i2 and j == j2 then
        if j > 1 then
            t[#t + 1] = 'UL';
            return shortest_path(n, i-2, j-1, i2, j2, t);
        else
            t[#t + 1] = 'UR';
            return shortest_path(n, i-2, j+1, i2, j2, t);
        end
    end
end
local n = read'n';
local priority = { UL=0, UR=1, R=2, LR=3, LL=4, L=5 };
local i, j, i2, j2 = read('n','n','n','n');
local path = shortest_path(n, i, j, i2, j2, { });
if path then
    table.sort(path, function(x,y)
    return priority[x] < priority[y];
    end);
    p(#path);
    p(concat(path, ' '));
else
    p'Impossible';
end