pots

#include<iostream>
#include<vector>
using namespace std;
struct SET{
    //set表示操作 1.FILL(a) 2.FILL(b) 3.DROP(a) 4.DROP(b) 5.POUR(a,b) 6.POUR(b,a)
    int a,b,father,set;
}op[10000010],opnow;
bool repeat[110][110];

int main()
{
    int a,b,c,f=0,l=1;
    scanf("%d%d%d",&a,&b,&c);
    op[0].a=0,op[0].b=0,op[0].father=-1,op[0].set=0;
    repeat[0][0]=1;
    while(f<l)
    {
        for(int i=1;i<=6;i++)
        {
            opnow=op[f];
            opnow.set=i,opnow.father=f;
            switch(opnow.set)
            {
                case 1:
                    opnow.a=a;
                    break;
                case 2:
                    opnow.b=b;
                    break;
                case 3:
                    opnow.a=0;
                    break;
                case 4:
                    opnow.b=0;
                    break;
                case 5:
                    if(opnow.a+opnow.b>=b)
                    {
                        opnow.a-=(b-opnow.b);
                        opnow.b=b;
                    }
                    else
                    {
                        opnow.b+=opnow.a;
                        opnow.a=0;
                    }
                    break;
                case 6:
                    if(opnow.a+opnow.b>=a)
                    {
                        opnow.b-=(a-opnow.a);
                        opnow.a=a;
                    }
                    else
                    {
                        opnow.a+=opnow.b;
                        opnow.b=0;
                    }
            }
            if(repeat[opnow.a][opnow.b]==1)
            {
                continue;
            }
            repeat[opnow.a][opnow.b]=1;
            op[l++]=opnow;
            if(opnow.a==c||opnow.b==c)
            {
                vector<int> ans;
                l--;
                while(1)
                {
                ans.push_back(op[l].set);
                l=op[l].father;
                if(l==-1)
                break;
                }
                int size=ans.size()-1;
                printf("%d\n",size);
                for(int i=size-1;i>=0;i--)
                {
                    switch(ans[i])
                    {
                        case 1:printf("FILL(1)\n"); break;
                        case 2:printf("FILL(2)\n"); break;
                        case 3:printf("DROP(1)\n"); break;
                        case 4:printf("DROP(2)\n"); break;
                        case 5:printf("POUR(1,2)\n"); break;
                        case 6:printf("POUR(2,1)\n"); break;
                    }
                }
                return 0;
            }
        }
    f++;
    }
    printf("impossible\n");
    return 0;
}