минимум 4 чисел

#include <iostream>

using namespace std;

int min (int a, int b, int c, int d)
{
  int n = 0;
  if ((a < c) && (a < b) && (a < d))
  n = a;
   if ((b < c) && (b < a) && (b < d))
  n = b;
   if ((c < a) && (c < b) && (c < d))
  n = c;
  if ((d < a) && (d < b) && (d < c))
  n = d;
return n;
}
int main ()
{
  int a, b, c, d;
  cin >> a >> b >> c >> d;
cout << min(a, b, c, d) << endl;
return 0;
}