#include <bits/stdc++.h>

using namespace std;

using Coords = pair<int, int>;

void moveTail(const Coords& head, Coords& tail){
    if(abs(head.first - tail.first) <= 1 && abs(head.second - tail.second) <= 1){
        return;
    }

    if(head.first == tail.first){
        if(head.second > tail.second){
            tail.second++;
        } else{
            tail.second--;
        }
    } else if(head.second == tail.second){
        if(head.first > tail.first){
            tail.first++;
        } else{
            tail.first--;
        }
    } else if(head.first > tail.first && head.second > tail.second){
        tail.first++;
        tail.second++;
    } else if(head.first < tail.first && head.second > tail.second){
        tail.first--;
        tail.second++;
    } else if(head.first > tail.first && head.second < tail.second){
        tail.first++;
        tail.second--;
    } else if(head.first < tail.first && head.second < tail.second){
        tail.first--;
        tail.second--;
    }
}

int main(){
    ifstream input_file("input.txt");
    string line;

    Coords head(0, 0), tail(0, 0);
    set<Coords> visited_by_tail;
    visited_by_tail.insert(tail);

    while(getline(input_file, line)){
        stringstream ss(line);
        char direction;
        int steps;

        ss >> direction >> steps;

        while(steps > 0){
            if(direction == 'R'){
                head.first++;
            } else if(direction == 'L'){
                head.first--;
            } else if(direction == 'U'){
                head.second++;
            } else if(direction == 'D'){
                head.second--;
            }
            moveTail(head, tail);
            visited_by_tail.insert(tail);
            steps--;

            // cout << head.first << " " << head.second << " " << tail.first << " " << tail.second << '\n';
        }
    }

    cout << "Number of positions visited by the tail: " << visited_by_tail.size() << endl;

    return 0;
}