题解 | 小红取数

#include <iostream>
#include<vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int>arr(n);
    for(int i = 0;i<n;++i){
        cin >> arr[i];
    }
    int sum = 0;
    for(int i = 0;i<n;++i){
        if(arr[i]%2!=0){
            sum++;
        }
    }
    if(sum==0){
        cout << -1;
    }else{
        cout << sum;
    }
}