#include<iostream>
#include<queue>
#include<cstring>
using namespace std;
#define maxn 105
int a,b,c;
bool visit[maxn][maxn];
struct node{
    int a,b,cnt,path[maxn*maxn];
    node(int ai,int bi,int cnti){
        a = ai;
        b = bi;
        cnt = cnti;
    }
};
const char msg[][15
 
] = {
    "FILL(1)",
    "FILL(2)",
    "DROP(1)",
    "DROP(2)",
    "POUR(1,2)",
    "POUR(2,1)"
};
typedef node Node;
void bfs(){
    memset(visit,false,sizeof visit);
    queue<Node>q;
    Node f(0,0,0);
    visit[0][0] = true;
    q.push(f);
    while(!q.empty()){
        f = q.front();q.pop();
        
 
if(f.a==c||f.b==c){
            cout<<f.cnt<<endl;
            for(int i=1;i<=f.cnt;i++){
                cout<<msg[f.path[i]]<<endl;
            }
            return;
        }
        Node v = f;
        v.cnt++;
        if(a-f.a>0){
            v.a = a;
            v.b 
 
= f.b;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt]=0;
                q.push(v);
            }
        }
        if(b-f.b>0){
            v.a = f.a;
            v.b = b;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 1;
                q.push(v);
            }
        }
        if(f.a){
            v.a = 0;
            v.b = f.b;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 2;
                q.push(v);
            }
        }
        if(f.b){
            v.a = f.a;
            v.b = 0;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 3;
                q.push(v);
            }
        }
        if(f.a>0&&f.b+f.a<=b){
            v.a = 0;
            v.b = f.b+f.a;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 4;
                q.push(v);
            }
        }
        if(f.a>0&&f.b+f.a>b){
            v.a = f.a-(b-f.b);
            v.b = b;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 4;
                q.push(v);
            }
        }
        if(f.b>0&&f.a+f.b<=a){
            v.a = f.a+f.b;
            v.b = 0;
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 5;
                q.push(v);
            }
        }
        if(f.b>0&&f.a+f.b>a){
            v.a = a;
            v.b = f.b-(a-f.a);
            if(!visit[v.a][v.b]){
                visit[v.a][v.b] = true;
                v.path[v.cnt] = 5;
                q.push(v);
            }
        }
    }
    printf("impossible\n");
}
int main(){
    scanf("%d%d%d",&a,&b,&c);
    bfs();
    return 0;
}