#include <iostream>
using namespace std;
static const int N = 100000;
int main(void){
  long long int l, n, w[N];

  cin >> l >> n;
  for(int i=0;i<n;i++) cin >> w[i];
  int block = 0, cnt = 1;
  for(int i=0;i<n;i++){
    block += w[i];
    while(block > l){
      block -= l; cnt++;
    }
  }

  cout << cnt << endl;  
}