6.1.1

#include <iostream>

using namespace std;

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