#include <bits/stdc++.h>
const double pi = acos(-1.0);
using namespace std;
inline long long MAX2(long long a, long long b) {
  return (a) > (b) ? (a) : (b);
}
inline long long MAX3(long long a, long long b, long long c) {
  return (a) > (b) ? ((a) > (c) ? (a) : (c)) : ((b) > (c) ? (b) : (c));
}
inline long long MIN2(long long a, long long b) {
  return (a) < (b) ? (a) : (b);
}
inline long long MIN3(long long a, long long b, long long c) {
  return (a) < (b) ? ((a) < (c) ? (a) : (c)) : ((b) < (c) ? (b) : (c));
}
int mod = 1e9 + 7;
int64_t extGcd(int64_t a, int64_t b, int64_t& x, int64_t& y) {
  if (!a) {
    x = 0;
    y = 1;
    return b;
  }
  int64_t x1, y1;
  int64_t d = extGcd(b % a, a, x1, y1);
  x = y1 - (b / a) * x1;
  y = x1;
  return d;
}
inline long long addmod(long long a, long long b) {
  a = a % mod + b % mod;
  if (a > mod) a %= mod;
  return a;
}
inline long long submod(long long a, long long b) {
  a = a % mod - b % mod;
  if (a < 0) a += mod;
  return a;
}
inline long long mulmod(long long a, long long b) {
  return (a % mod * b % mod) % mod;
}
int dx[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dy[] = {0, 1, 1, 1, 0, -1, -1, -1};
inline long long exp(long long a, long long b) {
  if (a == 0) return 0ll;
  long long r = 1LL;
  while (b > 0) {
    if (b & 1) {
      r = r * (a % mod);
      r = (r + mod) % mod;
    }
    b /= 2;
    a = (a % mod) * (a % mod);
    a = (a + mod) % mod;
  }
  return (r + mod) % mod;
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  if (a == 0) return b;
  return gcd(b, a % b);
}
unsigned long int setbits(long long n) {
  unsigned long int count = 0;
  while (n) {
    n &= (n - 1);
    count++;
  }
  return count;
}
int k;
vector<string> g1;
bool check(int mid) {
  int avail = mid;
  int lines = 1;
  for (int i = 0; i < g1.size(); i++) {
    string curr = g1[i];
    if (curr.size() > mid) return false;
    if (curr.size() == mid and i != (g1.size() - 1)) return false;
    if (avail > curr.size()) {
      avail = avail - (curr.size() + 1);
    } else if (avail == curr.size() and i == (g1.size() - 1)) {
      avail = 0;
    } else {
      lines++;
      avail = mid;
      avail = avail - (curr.size() + 1);
    }
  }
  return (lines <= k);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  if (fopen("input.txt", "r"))
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
  ;
  cin >> k;
  string temp;
  string s = "";
  while (cin >> temp) {
    s += temp;
    s += " ";
  }
  s = s.substr(0, s.size() - 1);
  for (long long i = (long long)(0); i < (long long)(s.size()); i++) {
    if (s[i] == '-') s[i] = ' ';
  }
  stringstream str(s);
  string word;
  while (str >> word) g1.push_back(word);
  int lo = 1;
  int hi = 1000000;
  int ans = 1;
  while (lo <= hi) {
    int mid = (lo + hi) / 2;
    if (check(mid)) {
      ans = mid;
      hi = mid - 1;
    } else {
      lo = mid + 1;
    }
  }
  cout << ans << '\n';
}
