#include <bits/stdc++.h>   using namespace std;   const int N = 200100;   const int INF = 1000 * 1000 * 100;   string s[N];   char ch[30];   int d[1000 * 3000 + 10], l[30], r[30];   int lcps(int x) {     int sz = s[x].size();     for (int i = sz - 1; i >= 0; i--)       r[i] = r[i + 1] + ((s[x][i] -  0 ) << (sz - i - 1));     l[0] = s[x + 1][0] -  0 ;     for (int i = 1; i < sz; i++) l[i] = l[i - 1] * 2 + (s[x + 1][i] -  0 );     for (int i = sz; i > 0; i--)       if (l[i - 1] == r[sz - i]) return i;     return 0;   }   int main() {     int n;     scanf( %d , &n);     for (int i = 0; i < n; i++) {       scanf( %20s , ch);       for (int j = 0; j < 20 && (ch[j] ==  0  || ch[j] ==  1 ); j++)         s[i] += ch[j];     }     int sz = s[0].size(), p = (1 << (sz + 1)), all(0), tmp(0);     fill(d, d + p, INF);     d[p - 1] = 0;     for (int i = 0; i < n; i++) {       int t = sz, mn = INF, z;       if (i) {         t = lcps(i - 1);         for (int j = 0; j <= sz; j++) {           if (j == 0) {             mn = min(all + sz - tmp, mn);             if (s[i][0] ==  0 )               z = p - 2;             else               z = 1;           } else {             mn = min(d[z] + sz - j, mn);             z *= 2;             if (j < sz) z += s[i][j] -  0 ;             z %= p;           }         }         z = 0;         mn -= (sz - t);         d[p - 1] = min(d[p - 1], mn);         for (int j = sz - 1; j >= 0; j--) {           int v = (1 << (sz - j - 1));           if (s[i - 1][j] -  0  == 1) {             z &= ((1 << (sz - j)) - 1);             if ((z & v) == 0) z += v;           } else {             z |= ((p - 1) ^ ((1 << (sz - j)) - 1));             if ((z & v) != 0) z -= v;           }           d[z] = min(d[z], mn);         }         tmp += (sz - t);         all += (sz - t);         all = min(all, mn + tmp);       } else         all += sz, tmp += sz, d[p - 1] = sz;     }     cout << all << endl;     return 0;   }   