/***IN THE NAME OF ALMIGHTY ALLAH***/
/***ALHAMDULILLAH***/
 
/***From dust I have come, dust I will be***/
#include <bits/stdc++.h>
using namespace std;
#define optimize()           \
    ios::sync_with_stdio(0); \
    cin.tie(0);
#define start \
    int T;    \
    cin >> T; \
    while (T--)
#define endl '\n'
#define pb push_back
#define ll long long
#define Yes cout << "Yes\n"
#define YES cout << "YES\n"
#define No cout << "No\n"
#define NO cout << "NO\n"
 
bool isPrime(int n)
{
    if(n<=1)
        return false;
 
    if(n<=3)
        return true;
 
    if(n%2==0||n%3==0)
        return false;
 
    for(int i=5; i*i<=n; i=i+6)
    {
        if(n%i==0||n%(i+2)==0)
            return false;
    }
 
    return true;
}
int main()
{
 
        ll x;
        cin >> x;
        cout << x-1971 << endl;
    return 0;
}