#include 
    
     #include 
     
      #include 
      
       using namespace std;int A,B,C,vis[101][101];char str[6][10] = {
    "FILL(1)", "FILL(2)", "DROP(1)", "DROP(2)", "POUR(1,2)", "POUR(2,1)"};structnode{
        int num,a,b;    node *pre;};node que[101*101];void print(node now){
        if (now.pre)    {
            print(*now.pre);        printf("%s\n",str[now.num]);    }}void BFS(){
        int step=0,head=0,tail=1,count,water1,water2;    que[0].a=que[0].b=0;    que[0].pre=0;    while (tail-head>0)    {
            count=tail-head;        while (count--)        {
                node now=que[head];            if (now.a==C || now.b==C)            {
                    printf("%d\n",step);                print(now);                return;            }            if(!vis[A][now.b])            {
                    vis[A][now.b]=1;                que[tail].num=0;                que[tail].a=A;                que[tail].b=now.b;                que[tail++].pre=&que[head];            }            if(!vis[now.a][B])            {
                    vis[now.a][B]=1;                que[tail].num=1;                que[tail].a=now.a;                que[tail].b=B;                que[tail++].pre=&que[head];            }            if(!vis[0][now.b])            {
                    vis[A][now.b]=1;                que[tail].num=2;                que[tail].a=0;                que[tail].b=now.b;                que[tail++].pre=&que[head];            }            if(!vis[now.a][0])            {
                    vis[now.a][0]=1;                que[tail].num=3;                que[tail].a=now.a;                que[tail].b=0;                que[tail++].pre=&que[head];            }            water1=min (now.a,B-now.b);            if(!vis[now.a-water1][now.b+water1])            {
                    vis[now.a-water1][now.b+water1]=1;                que[tail].num=4;                que[tail].a=now.a-water1;                que[tail].b=now.b+water1;                que[tail++].pre=&que[head];            }            water2=min (A-now.a,now.b);            if(!vis[now.a+water2][now.b-water2])            {
                    vis[now.a+water2][now.b-water2]=1;                que[tail].num=5;                que[tail].a=now.a+water2;                que[tail].b=now.b-water2;                que[tail++].pre=&que[head];            }            head++;        }        step++;    }    printf("impossible\n");}int main (){
        scanf("%d%d%d",&A,&B,&C);    memset(vis,0,sizeof(vis));    vis[0][0]=1;    BFS();    return 0;}