寒假作业打卡

#include <iostream>

using namespace std;
int x;

int main(void) {
  int ans = 0, last_score = -1;
  while (scanf("%d", &x), x) {
    if (x == 1) {
      ++ans;
      last_score = 1;
    } else {
      if (last_score == -1 || last_score == 1) {
        ans += 2;
        last_score = 2;
      } else {
        ans += last_score + 2;
        last_score += 2;
      }
    }
  }
  printf("%d\n", ans);
  return 0;
}