C++ :

#include<bits/stdc++.h>
using namespace std;

int main(){
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	int sum=0;
	sum=max(a,b);
	sum=max(sum,c);
	cout<<sum;
}

Python :

# coding=utf-8
x=float(input())
y=float(input())
z=float(input())
if x>y and x>z:
    print(int(x))
if y>x and y>z:
    print(int(y))
if z>x and z>y:
    print(int(z))