Language: C++

#include <bits/stdc++.h>
using namespace std;

#define ms(s, n) memset(s, n, sizeof(s))
#define f(i, a, b) for (int i = (a); i <=(b); i++)
#define FORd(i, a, b) for (int i = (a) - 1; i >= (b); i--)
#define FORall(it, a) for (__typeof((a).begin()) it = (a).begin(); it != (a).end(); it++)
#define sz(a) int((a).size())
#define present(t, x) (t.find(x) != t.end())
#define all(a) (a).begin(), (a).end()
#define uni(a) (a).erase(unique(all(a)), (a).end())
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define prec(n) fixed<<setprecision(n)
#define bit(n, i) (((n) >> (i)) & 1)
#define bitcount(n) __builtin_popcountll(n)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pi;
typedef vector<ll> vi;
typedef vector<pi> vii;
const int MOD = (int) 1e9 + 7;
const int MOD2 = MOD + 2; //1007681537;
const int INF = (int) 1e9;
const ll LINF = (ll) 1e18;
const ld PI = acos((ld) - 1);
const ld EPS = 1e-9;
inline ll gcd(ll a, ll b) {ll r; while (b) {r = a % b; a = b; b = r;} return a;}
inline ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
inline ll fpow(ll n, ll k, int p = MOD) {ll r = 1; for (; k; k >>= 1) {if (k & 1) r = r * n % p; n = n * n % p;} return r;}
template<class T> inline int chkmin(T& a, const T& val) {return val < a ? a = val, 1 : 0;}
template<class T> inline int chkmax(T& a, const T& val) {return a < val ? a = val, 1 : 0;}
inline ll isqrt(ll k) {ll r = sqrt(k) + 1; while (r * r > k) r--; return r;}
inline ll icbrt(ll k) {ll r = cbrt(k) + 1; while (r * r * r > k) r--; return r;}
inline void addmod(int& a, int val, int p = MOD) {if ((a = (a + val)) >= p) a -= p;}
inline void submod(int& a, int val, int p = MOD) {if ((a = (a - val)) < 0) a += p;}
inline int mult(int a, int b, int p = MOD) {return (ll) a * b % p;}
inline int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}
inline int sign(ld x) {return x < -EPS ? -1 : x > +EPS;}
inline int sign(ld x, ld y) {return sign(x - y);}
int modulo(int a, int b) { return (a % b + b) % b; }
#define db(x) cerr << #x << " = " << (x) << " ";
#define endln cerr << "\n";

int main()
{
	IOS;
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	ll n,k;
	cin >> n>>k;
	vi a(n);
	f(i, 0, n - 1){
		cin >> a[i];
	}
	sort(a.begin(),a.end());
	ll sum=0;
	for(i,0,k-1){
		sum+=a[i];
	}
	cout << sum << endl;
	// read the stuff at the bottom
	return 0;
}
/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
	* use int when constraints limits are tight
	* Time taken : global variable < pass by refernce < pass by value
	* It takes significant amt. of time in pass by value
*/





























Compiler output:
a.cc: In function 'int main()':
a.cc:65:13: error: 'i' was not declared in this scope
   65 |         for(i,0,k-1){
      |             ^
a.cc:70:9: error: expected primary-expression before 'return'
   70 |         return 0;
      |         ^~~~~~
a.cc:68:29: error: expected ')' before 'return'
   68 |         cout << sum << endl;
      |                             ^
      |                             )
   69 |         // read the stuff at the bottom
   70 |         return 0;
      |         ~~~~~~               
a.cc:65:12: note: to match this '('
   65 |         for(i,0,k-1){
      |            ^