#include using namespace std; #define int long long #define rep(i,l,r) for(int i=(int)(l);i<(int)(r);i++) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)x.size()) templatebool chmax(T &a,T b){if(abool chmin(T &a,T b){if(a>b){a=b;return 1;}return 0;} typedef pair pii; typedef vector vi; typedef vector vvi; const int inf = 1LL<<60; const int mod = 1e9 + 7; const double eps = 1e-9; /*{ }*/ signed main(){ int d; cin >> d; string s, t; rep(i, 0, 14) s += "x"; cin >> t; s += t; cin >> t; s += t; rep(i, 0, 15) s += "x"; int ans = 0; rep(i, 0, sz(s)){ t = s; if(s[i] == 'x'){ rep(j, 0, d){ if(s[i+j] == 'o') break; t[i+j] = 'o'; } } int cnt = 0; rep(j, 0, sz(s)){ if(t[j] == 'o') cnt++; else{ chmax(ans, cnt); cnt = 0; } } // cout << t << endl; } cout << ans << endl; return 0; }