#include "bits/stdc++.h" #define rep(i,n) for(int i = 0;i < n;i++) #define REP(i,n,k) for(int i = n;i < k;i++) #define P(p) cout << (p) << endl; #define sP(p) cout << setprecision(15) << fixed << p << endl; #define pi 3.1415926535 #define IINF 1e9 #define LINF 1e18 #define vi vector #define mp make_pair using namespace std; typedef long long ll; typedef unsigned long long ull; int dx[] = { 0, 1, 0, -1 }; int dy[] = { -1, 0, 1, 0 }; unsigned long long sttoi(std::string str) { unsigned long long ret; std::stringstream ss; ss << str; ss >> ret; return ret; } ull gcd(ull a, ull b){ if (b > a)swap(a, b); if (b == 0) return a; return gcd(b, a%b); } void solve() { int n; cin >> n; string s,t; cin >> s >> t; s ="xxxxxxxxxxxxxx" + s + t + "xxxxxxxxxxxxxx"; int maxi = -1; rep(i,s.length()){ int streak = 0; bool can = true; for(int k = 0;k <= n;k++){ rep(j,k){ if(s[i+j]=='o')can = false; } if(can){ string tmp = s; rep(j,k){ tmp[i+j] = 'o'; } streak = 0; rep(j,tmp.length()){ if(tmp[j] == 'o'){ streak++; }else{ maxi = max(maxi,streak); streak = 0; } } } } } P(maxi); } int main() { solve(); return 0; }