Untitled

#include <iostream>
#include <array>
#include <algorithm>

int main() {
    using namespace std;
    unsigned N;
    cin >> N;
    string S;
    cin >> S;

    array<unsigned, 3> dp{};
    auto&& [rock, scissors, paper]{dp};

    for(const auto c : S){
        // Moves are limited to those not equal to the previous one
        dp = {max(scissors, paper), max(rock, paper), max(rock, scissors)};
        // Losing move must not be made = maximum winning count is 0
        // Making winning move increases the maximum value +1
        if (c == 'R') {
            scissors = 0;
            ++paper;
        } else if (c == 'S') {
            paper = 0;
            ++rock;
        } else if (c == 'P') {
            rock = 0;
            ++scissors;
        }
    }

    cout << ranges::max(dp) << endl;

    return 0;
}