C :

#include<stdio.h>
#include<math.h>
int main()
{
	int i,m,n,a,k,fj,sj,js=0,j;
	scanf("%d%d",&m,&n);
	for(i=m;i<=n;i++)
	{
		a=i;k=2;
	
		
		while(a!=1)
		{   
		   fj=0;
			if(a%(k*k)==0)
			while(a%k==0)
			a=a/k;
			else k++;
			if(k>sqrt(a)&&a!=1)  {fj=1;break;} 
			}
			a=i+1;k=2;
			if(fj==0)
			{
			while(a!=1)
		{   sj=0;
			if(a%(k*k)==0)
			while(a%k==0)
			a=a/k;
			else k++;
			if(k>sqrt(a)&&a!=1)  {sj=1;break;}
			}	
		}
			if(sj==0) 
			{
				printf("%d %d\n",i,i+1);js++;
			}
	}
	if(js==0) printf("no find");
	return 0;
}

C++ :

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

bool f(int x) {
	while (x != 1) {
		int t = x;
		for (int i = 2; i <= x/i; i ++) {
			int cnt = 0;
			while (x%i==0) {
				x /= i;
				cnt ++;
			}
			
			if (cnt == 1) return false;
			if (cnt > 1) break;
		}
		if (x == t) return false;
	}
	
	return true;	
}

int main() {
	int m, n;
	cin >> m >> n;
	
	bool flag = true;
	for (int i = m; i < n; i ++) {
		if (f(i) && f(i+1)) {
			cout << i << ' ' << i + 1 << endl;
			flag = false;
		}
	}
	
	if (flag) cout << "no find" << endl;
	
	return 0;
}