#include <iostream>
#include <vector>
#include <cmath>

using namespace std;

int main() {

    int nmbTiles;
    string input;

    cin >> nmbTiles;
    cin >> input;

    vector<int> xCount;
    vector<int> oCount;
    int xSum = 0;
    int oSum = 0;
    xCount.push_back(xSum);
    oCount.push_back(oSum);
    for (int i = 0; i < input.size(); i++) {
        if (input[i] == 'X') {
            xSum++;
        } else {
            oSum++;
        }
        xCount.push_back(xSum);
        oCount.push_back(oSum);
    }

    int out = 0;
    for (size_t right = 0; right <= input.size(); right++) {
        for (int left = 0; left < right; left++) {
            int xInside = xCount[right] - xCount[left];
            int oInside = oCount[right] - oCount[left];

            if (oInside == 0 || xInside < 8) {
                break;
            }

            int n = (int)sqrt(oInside);
            if (n * n != oInside) {
                continue; // skip if O is not n^2
            }

            int xExpected = 4 * n + 4;
            if (xInside == xExpected) {
                out++;
            }
        }
    }
    int out2 = 0;
    for (size_t right = 0; right <= input.size(); right++) {
        for (int left = 0; left < right; left++) {
            int oInside = xCount[right] - xCount[left];
            int xInside = oCount[right] - oCount[left];
            if (oInside == 0 || xInside < 8) {
                break;
            }

            int n = (int)sqrt(oInside);
            if (n * n != oInside) {
                continue; // skip if O is not n^2
            }


            if (xInside == 4 * n + 4) {
                out2++;
            }
        }
    }

    int sum = out + out2;
    cout << sum << endl;
//
//    int out = 0;
//    for (size_t i = 0; i < input.size(); i++) {
//        for (int j = 0; j < i; j++) {
//
//            int xCount = 0, oCount = 0;
//            for (int k = j; k <= i; k++) {
//                if (input[k] == 'X') {
//                    xCount++;
//                } else {
//                    oCount++;
//                }
//            }
//
//            int n = (int)sqrt(oCount);
//            if (n * n != oCount || oCount == 0) {
//                continue; // skip if O is not n^2
//            }
//
//            if (xCount == 4 * n + 4) {
//                out++;
//            }
//        }
//    }
//
//    int out2 = 0;
//    for (size_t i = 0; i < input.size(); i++) {
//        for (int j = 0; j < i; j++) {
//
//            int xCount = 0, oCount = 0;
//            for (int k = j; k <= i; k++) {
//                if (input[k] == 'O') {
//                    xCount++;
//                } else {
//                    oCount++;
//                }
//            }
//
//            int n = (int)sqrt(oCount);
//            if (n * n != oCount || oCount == 0) {
//                continue; // skip if O is not n^2
//            }
//
//            if (xCount == 4 * n + 4) {
//                out2++;
//            }
//        }
//    }
//
//    int sum = out + out2;
//    cout << sum << endl;
    return 0;
}