Language: C

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef vector<vector<pair<int, int> > > vvp;
typedef vector<pair<int, int> > vp;
typedef vector<int> vi;
typedef vector<vi > vvi;
typedef vector<vvi > vvvi;
typedef vector<vector<ll> > vvl;
typedef vector<ll> vl;
typedef vector<vector<double> > vvd;
typedef vector<double> vd;
typedef vector<vector<bool> > vvb;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef pair<string, int> psi;
typedef pair<int, int> pii;
//#define unix ((unsigned int)time(NULL))
#define rep(i,s,n) for(int i = (s); i < (n); i++)
#define inputv(v) for(int i = 0; i < (v.size()); i++)cin>>v[i];
#define inputvv(v) for(int i = 0; i < (v.size()); i++)for(int j=0;j<(v[0].size());j++)cin>>v[i][j];
#define all(x) (x).begin(), (x).end()
#define yn(f) cout <<(f?"yes":"no")<< endl
#define YN(f) cout <<(f?"YES":"NO")<< endl
#define Yn(f) cout <<(f?"Yes":"No")<< endl
const int inf = 1e9 + 7;
void print() {
	cout << endl;
}
template <class T>
void print(T a) {
	cout << (a) << endl;
}
template <class Head, class... Tail>
void print(Head&& head, Tail&& ... tail) {
	cout << head;
	if (sizeof...(tail) == 0) {
		print();
	}
	else {
		cout << " ";
		print(forward<Tail>(tail)...);
	}

}
void print(pair<int, int> A) {
	cout << "(" << A.first << "," << A.second << ")" << endl;;
}
void print(vector<pair<int, int> >& A) {
	for (int i = 0; i < A.size(); i++)
	{
		cout << "(" << A[i].first << "," << A[i].second << ")";
		if (A.size() - 1 == i) {
			cout << endl;
		}
		else {
			cout << " ";
		}
	}
}
void print(vector<vector<pair<int, int> > >& A) {
	for (int i = 0; i < A.size(); i++)
	{
		print(A[i]);
	}
}
template <class T>
void print(vector<T>& A) {
	for (int i = 0; i < A.size(); i++)
	{
		cout << A[i];
		if (A.size() - 1 == i) {
			cout << endl;
		}
		else {
			cout << " ";
		}
	}
}
template <class T>
void print(const vector<T>& A) {
	for (int i = 0; i < A.size(); i++)
	{
		cout << A[i];
		if (A.size() - 1 == i) {
			cout << endl;
		}
		else {
			cout << " ";
		}
	}
}
template<class T>
void print(vector<vector<T> >& A) {
	for (int i = 0; i < A.size(); i++)
	{
		print(A[i]);
	}
}
template<class T>
void print(const vector<vector<T> >& A) {
	for (int i = 0; i < A.size(); i++)
	{
		print(A[i]);
	}
}
class disjoint_set {
public:
	vi p, rank;
	disjoint_set(int size) {
		p.resize(size, 0);
		rank.resize(size, 0);
		for (int i = 0; i < size; i++)makeSet(i);
	}
	void makeSet(int x) {
		p[x] = x;
		rank[x] = 0;
	}
	bool same(int x, int y) {
		return findSet(x) == findSet(y);
	}
	void unite(int x, int y) {
		link(findSet(x), findSet(y));
	}
	void link(int x, int y) {
		if (rank[x] < rank[y]) {
			p[x] = y;
		}
		else {
			p[y] = x;
			if (rank[x] == rank[y]) {
				rank[x]++;
			}
		}
	}
	int findSet(int x) {
		if (x != p[x]) {
			p[x] = findSet(p[x]);
		}
		return p[x];
	}
};
class rmq {
public:
	int n, inf_, max_n;
	vi A;
	rmq(int n_) {
		n = 1;
		inf_ = INT_MAX;
		max_n = (1 << 18);
		while (n < n_)n *= 2;
		A.resize(max_n * 2 - 1);
		for (int i = 0; i < n * 2 - 1; i++)A[i] = inf_;
	}
	void update(int i, int x) {
		i += n - 1;
		A[i] = x;
		while (i > 0) {
			i = (i - 1) / 2;
			A[i] = min(A[i * 2 + 1], A[i * 2 + 2]);
		}
	}
	int query(int left, int right, int i = 0, int left2 = 0, int right2 = -1) {
		if (right2 == -1)right2 = n;
		if (right2 <= left || right <= left2) {
			return inf_;
		}
		if (left <= left2 && right2 <= right) {
			return A[i];
		}
		else {
			int mid = (left2 + right2) / 2;
			return min(query(left, right, i * 2 + 1, left2, mid), query(left, right, i * 2 + 2, mid, right2));
		}
	}
};
class rsq {//遅延セグ木
public:
	int n, max_n;
	vl A, Lazy;
	rsq(int n_) {
		n = 1;
		max_n = (1 << 18);
		while (n < n_)n *= 2;
		A.resize(max_n * 2 - 1);
		Lazy.resize(max_n * 2 - 1);
	}
	void propagate(int i, int left, int right) {
		if (Lazy[i] != 0) {
			A[i] += Lazy[i];
			if (right - left > 1) {
				Lazy[i * 2 + 1] += Lazy[i] / 2;
				Lazy[i * 2 + 2] += Lazy[i] / 2;
			}
			Lazy[i] = 0;
		}
	}
	void add(int left, int right, int x, int i = 0, int left2 = 0, int right2 = -1) {
		if (right2 == -1)right2 = n;
		propagate(i, left2, right2);
		if (right <= left2 || right2 <= left) return;

		if (left <= left2 && right2 <= right) {
			Lazy[i] += (right2 - left2) * x;
			propagate(i, left2, right2);

		}
		else {
			int mid = (left2 + right2) / 2;
			add(left, right, x, i * 2 + 1, left2, mid);
			add(left, right, x, i * 2 + 2, mid, right2);
			A[i] = A[i * 2 + 1] + A[i * 2 + 2];
		}

	}
	ll sum(int left, int right, int i = 0, int left2 = 0, int right2 = -1) {
		if (right2 == -1)right2 = n;
		if (right2 <= left || right <= left2) return 0;
		propagate(i, left2, right2);
		if (left <= left2 && right2 <= right) {
			return A[i];
		}
		else {
			int mid = (left2 + right2) / 2;
			ll res = 0;
			res += sum(left, right, i * 2 + 1, left2, mid);
			res += sum(left, right, i * 2 + 2, mid, right2);
			return res;
		}
	}
};
void dedupe(vi& A) {
	sort(A.begin(), A.end());
	A.erase(unique(A.begin(), A.end()), A.end());
}
int extgcd(int a, int b, int& x, int& y) {// log N
	int d = a;
	if (b == 0) {
		x = 1;
		y = 0;
	}
	else {
		d = extgcd(b, a % b, y, x);
		y -= (a / b) * x;
	}
	return d;
}
ll merge_count(vi & A) {//N log N
	const int inf = 1000000007;
	int n = A.size();
	if (n <= 1)return 0;
	long long count = 0;
	int mid = n / 2;
	vector<int> B(A.begin(), A.begin() + mid);
	vector<int> C(A.begin() + mid, A.end());
	count += merge_count(B);
	count += merge_count(C);
	B.push_back(inf);
	C.push_back(inf);
	int B_i = 0;
	int C_i = 0;
	for (int i = 0; i < n; i++) {
		if (B[B_i] <= C[C_i]) {
			A[i] = B[B_i++];
		}
		else {
			count += (n / 2) - B_i;
			A[i] = C[C_i++];
		}
	}
	return count;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
int main() {
    int a,b;cin>>a>>b;
    cout<<a*b<<endl;
}

Compiler output:
main.c:1:10: fatal error: bits/stdc++.h: No such file or directory
    1 | #include "bits/stdc++.h"
      |          ^~~~~~~~~~~~~~~
compilation terminated.