int main()
{
	int a=0,b=0,n=0,c=0,d=0,p=0;
	cout << "wpisz liczbe naturalna: ";
	cin>>n;
	if (n<0) {
		cout << "n musi byc wieksze od 0";
	}
	else {
		while (p!=n) {
		do {
			a=a+1;
			p=a*a+b*b+c*c+d*d;
			//cout <<"1   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;
			if (p>n){
				a=a-1;
				do {
					b=b+1;
					p=a*a+b*b+c*c+d*d;
					//cout <<"2   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;
					if (b>sqrt(n-(p-(b*b)))){
						b=b-1;
						do {
							c=c+1;
							p=a*a+b*b+c*c+d*d;
							//cout <<"3   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;
							if (c>sqrt(n-(p-(c*c)))){
								c=c-1;
								do {
									d=d+1;
									p=a*a+b*b+c*c+d*d;
								    //cout <<"4   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;

								} while (p<n);
							}
						} while (p<n);
					}
				} while (p<n);
			}

		} while (p<n);
		if (p>n) {
			int i=0;
		    i=i+1;
			a=a-i;
			b=0;
			c=0;
			d=0;
			do {
				b=b+1;
				p=a*a+b*b+c*c+d*d;
				//cout <<"2   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;
				if (b>sqrt(n-(p-(b*b)))){
					b=b-1;
					do {
						c=c+1;
						p=a*a+b*b+c*c+d*d;
						//cout <<"3   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;
						if (c>sqrt(n-(p-(c*c)))){
							c=c-1;
							do {
								d=d+1;
								p=a*a+b*b+c*c+d*d;
								//cout <<"4   "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p<<endl;

							} while (p<n);
						}
					} while (p<n);
				}
			} while (p<n);
		}
		}
	}
	cout <<"mozna ja przedstawic za pomoca kwadratow 4 liczb naturalnych: "<<a<<"   "<<b<<"   "<<c<<"   "<<d<<"   "<<p;


}