#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
#define int long long
#define ld long double
#define pii pair<int,int>
#define rand() abs((rand()<<15)|rand())
#define randll() abs(((long long)rand()<<30)|rand())
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
long long seed;
asm("rdtsc" : "=A"(seed));
srand(seed);
int n, m;
cin >> n >> m;
if(n == 1) {
vector<int> grid(m+1, 0);
int totalOnes = 0;
for(int i = 1; i <= m; i++) {
cin >> grid[i];
if(grid[i])
totalOnes++;
}
int ans = 1ll<<29;
int carried = totalOnes;
for(int i = 1; i <= m; i++) {
if(grid[i] == 1) {
carried--;
carried = min(carried, totalOnes-1);
ans = min(ans, carried);
} else {
carried++;
carried = min(carried, totalOnes+1);
ans = min(ans, carried);
}
}
cout << ans << endl;
} else {
}
}
