大家那么多人都发了题解，我也来凑个热闹(・∇・）

#include<iostream>
using namespace std;
int main()
{
	int a;
	cin >> a;
	cout << a % 10;
	return 0;
}

#include<iostream>
using namespace std;
int main(){
	string a;
	cin>>a;
	cout<<a[a.size()-1];
	return 0;
}

#include<iostream>
using namespace std;
int main()
{
	int a;
	cin >> a;
	cout << a % 10;
	return 0;
}

Note:
****************************************/
#include <queue>
#include <math.h>
#include <stack>
#include <vector>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <iomanip>
#include <string.h>
#include <cstring>
#include <algorithm>
#define int long long
using namespace std;
const int N = 1e6 + 10;
const int INF = 0x3f3f3f3f;
int n;
signed main(){
	cin >> n;
	cout << n % 10 << endl;
	return 0;
}

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
const int N=1e7+10;
const int INF=0x3f3f3f3f;
int main()
{
	int a;
	cin>>a;
	cout<<a%10;
}

#include <bits/stdc++.h> using namespace std; int a,f; int main() { cin >> a; f = a % 10; cout << f; }

#include <stdio.h> #include <iostream using namespace std; int main( ) { int n; cin>>n; x=n%10 cout<<x; }

#include <iostream>

using namespace std;

int main() { int a;

cin >> a;

cout << a % 10;

return 0;

}

#include <bits/stdc++.h>

using namespace std;

int main(void)
{
	int a;
	
	cin >> a;
	
	cout << a % 10;
	
	return 0;
}

#include <stdio.h>

#include <iostream>

using namespace std;

int main()

{

int a;
cin >> a ;
cout << a % 10;

}

#include <stdio.h> #include <iostream> using namespace std; int main() { int n; cin >> n; int x; x = n%10; cout << x; }

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int x;
	x = n%10;
	cout << x;
}

#include<iostream> using namespace std; int main(){ int a; cin >> a ; while (a > 10){ a = a % 10; } cout << a << endl; }