我也不知道是代码的问题（能过样例）还是远端评测不稳定

$Code：$

#include<bits/stdc++.h>
using namespace std;

int main() {
    int n, mx, cur;
    double time;
    string s;
    cin >> n >> s;
    s = " " + s;
    mx = cur = 0;
    time = 0;

    for (int i = 1; i <= n; i++) {
        if (s[i] == '>') {
            cur++;
            time += 1.0 / (cur + 1);
        } else {
            mx = max(mx, cur);
            cur = 0;
            time += 1;
        }
    }

    time -= 1;
    time += 1.0 / (mx + 2);

    printf("%.15g", time);
    return 0;
}