//新生训练

#include <iostream>
#include <algorithm>
#include <cstring>
#include <queue>
using namespace std;
typedef pair<int, int> PII;
const int N = 205;
int n, m;
int l;
int A, B, C;
int dis[N][N];struct node
{int px, py, op;
};node pre[N][N];void dfs(int x, int y)
{if (x == 0 && y == 0){return;}dfs(pre[x][y].px, pre[x][y].py);switch (pre[x][y].op){case 1:cout << "FILL(1)\n";break;case 2:cout << "FILL(2)\n";break;case 3:cout << "DROP(1)\n";break;case 4:cout << "DROP(2)\n";break;case 5:cout << "POUR(1,2)\n";break;case 6:cout << "POUR(2,1)\n";}
}bool flag = 1;void bfs()
{queue<PII> q;q.push(make_pair(0, 0));dis[0][0] = 0;while (!q.empty()){PII t = q.front();q.pop();int x = t.first, y = t.second;if (x == C || y == C){cout << dis[x][y] << '\n';dfs(x, y);flag = 0;return;}int ix, iy;// FILL(1)ix = A, iy = y;if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 1};q.push(make_pair(ix, iy));}// FILL(2)ix = x, iy = B;if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 2};q.push(make_pair(ix, iy));}// DROP(1)ix = 0, iy = y;if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 3};q.push(make_pair(ix, iy));}// DROP(2)ix = x, iy = 0;if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 4};q.push(make_pair(ix, iy));}// POUR(1,2)ix = x, iy = y;while (ix && iy < B){--ix;++iy;}if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 5};q.push(make_pair(ix, iy));}// POUR(2,1)ix = x, iy = y;while (iy && ix < A){++ix;--iy;}if (dis[ix][iy] == -1){dis[ix][iy] = dis[x][y] + 1;pre[ix][iy] = {x, y, 6};q.push(make_pair(ix, iy));}}
}void solve()
{memset(dis, -1, sizeof dis);cin >> A >> B >> C;bfs();if (flag)cout << "impossible";
}signed main()
{int t = 1;// cin>>t;while (t--){solve();}return 0;
}

//感谢学长的讲解 hwh ；

~~~//仅当笔者个人备忘录使用。