input()
a=[*map(int,input().split())]
print(['chest','biceps','back'][max(0,1,2,key=lambda i: sum(a[i::3]))])
#include <iostream>
using namespace std;
int main()
{
int n,a[3]={0,0,0},b;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>b;
a[i%3]+=b;
}
if(a[0]>a[1]&&a[0]>a[2])
cout<<"chest"<<endl;
if(a[1]>a[0]&&a[1]>a[2])
cout<<"biceps"<<endl;
if(a[2]>a[1]&&a[2]>a[0])
cout<<"back"<<endl;
return 0;
}
1505A - Is it rated - 2 | 169A - Chores |
765A - Neverending competitions | 1303A - Erasing Zeroes |
1005B - Delete from the Left | 94A - Restoring Password |
1529B - Sifid and Strange Subsequences | 1455C - Ping-pong |
1644C - Increase Subarray Sums | 1433A - Boring Apartments |
1428B - Belted Rooms | 519B - A and B and Compilation Errors |
1152B - Neko Performs Cat Furrier Transform | 1411A - In-game Chat |
119A - Epic Game | 703A - Mishka and Game |
1504C - Balance the Bits | 988A - Diverse Team |
1312B - Bogosort | 1616B - Mirror in the String |
1660C - Get an Even String | 489B - BerSU Ball |
977C - Less or Equal | 1505C - Fibonacci Words |
1660A - Vasya and Coins | 1660E - Matrix and Shifts |
1293B - JOE is on TV | 1584A - Mathematical Addition |
1660B - Vlad and Candies | 1472C - Long Jumps |