import std.conv, std.functional, std.range, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken.to!int; } long readLong() { return readToken.to!long; } real readReal() { return readToken.to!real; } bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } } bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } } int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; } int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); } int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); } enum N = 14; void main() { try { for (; ; ) { const D = readInt(); string A; A ~= readToken(); A ~= readToken(); const n = D + N + D; int ans; foreach (i; 0 .. D + N + 1) { auto bs = new bool[D + N + D]; foreach (j; 0 .. N) { bs[D + j] = (A[j] == 'o'); } if (bs[i .. i + D].any) { continue; } bs[i .. i + D] = true; for (int x = 0, y; x < D + N + D; x = y) { for (y = x; y < D + N + D && bs[x] == bs[y]; ++y) {} if (bs[x]) { chmax(ans, y - x); } } } writeln(ans); } } catch (EOFException e) { } }