Finding the max out of four numbers : In C++

Code :
#include <iostream>
#include <cstdio>
using namespace std;
int max_of_four(int a, int b, int c, int d){
    int max = a;
    if(max<b){
        max = b;
    }
    if(max<c)
        max = c;
    if(max<d)
        max = d;
    return max;
}
int main() {
    int a, b, c, d;
    cin>>a>>b>>c>>d;
    int ans = max_of_four(a, b, c, d);
    printf("%d", ans);
    return 0;
}