include <bits/stdc++.h>

using namespace std; int flu(int a[], int l, int r, int x) { while (l <= r) { int m = l + (r - l) / 2; if (a[m] == x) return m-1; else if (a[m] < x) l = m+1; else r = m-1; } return 0; } int main() { int n; cin >> n; int a[n]; for (int i = 0; i < n; i++) cin >> a[i]; sort(a, a + n); cout << flu(a, 0, n - 1, 7); }

//mảng cộng dồn

include <iostream>

using namespace std; long long a[10000007]; void check(long long b){ long long t=0; for(long long i=1;i<b;i++){ a[i]=a[i-1]+a[i]; } } int main() { long long n; cin>>n; for(long long i=0;i<n;i++) cin>>a[i]; check(n); for(long long i=1;i<n;i++) cout<<a[i]<<" ";

}

//mảng đánh dấu

include<bits/stdc++.h>

using namespace std; long long kt(long long x){ long long t = 0; while(x > 0){ t += x % 10; x /= 10; } return t; }

int main(){ int n; cin >> n;

vector<long long> a(n);
for(int i = 0; i < n; i++) cin >> a[i];

long long cnt[200]={0};

for(int i = 0; i < n; i++){
    cnt[kt(a[i])]++;
}

long long tong = 0;

for(int i = 0; i < 200; i++){
    long long k = cnt[i];
    tong += k * (k - 1) / 2;
}

cout << tong;

}