#include<iostream>
using namespace std;

int main()
{
    int a, b, c, cv;
    cout<<"Nhap vao canh a: ";
    cin>>a;
    cout<<"Nhap vao canh b: ";
    cin>>b;
    cout<<"Nhap vao canh c: ";
    cin>>c;
    if( a<b+c && b<a+c && c<a+b )
    {
        cv = a + b + c;
        cout << "Chu vi tam giac la: " << cv;
    }
    else
    {
        cout << "Day khong phai la tam giac";
    }
}

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

int a,b,c;

int main()
{
 cout<<"Nhap vao 3 so bat ki: ";cin>>a>>b>>c;
 if (a+b>c && b+c>a && a+c>b){
      cout<<"Day la tam giac"<<endl;
      cout<<"Chu vi: "<<a+b+c;
   } else cout<<"Day khong la tam giac"<<endl;
}