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

using ll = long long;
#define rep(i,n) for(ll i=0;i<ll(n);i++)
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vvvvll = vector<vvvll>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vvvb = vector<vvb>;
using vvvvb = vector<vvvb>;

bool DEB = 0;

bool isbool(ll N){
    if(N<=1)return 0;
    for(ll i=2;i*i<=N;i++){
        if(N%i==0)return 0;
    }
    return 1;
}

ll modPow(ll a,ll n,ll mod){
    a%=mod;
    if(n==0)return 1;
    if(n%2==1)return (modPow(a,n-1,mod)*a)%mod;
    ll res=modPow(a,n/2,mod);
    return (res*res)%mod;
}

void solve(){
    ll N,M;
    cin>>N>>M;
    if(M==1){
        cout<<0<<endl;
    }
    else if(N==0){
        cout<<1<<endl;
    }
    else if(N>=M){
        cout<<0<<endl;
        return;
    }
    else if(N<=5e5){
        ll res=1;
        for(ll i=1;i<=N;i++)res=(res*i)%M;
        cout<<res<<endl;
        return;
    }
    else if(!isbool(M)){
        cout<<0<<endl;
        return;
    }
    else{
    ll res=M-1;
    ll pm=1;
    for(ll n=M-1;n>N;n--){
        pm*=n;
        pm%=M;
    }
    pm=modPow(pm,M-2,M);res*=pm;
    res%=M;
    cout<<res<<endl;
    }
}

int main() {

    ll A,B;
    cin>>A>>B;
    ll m=(B*60*12)%43200;
    ll h=(A*3600+B*60)%43200;
    if(h<m)h+=43200;
    double cnt=0;
    while(m<h){
        cnt++;
        h+=1;
        m+=12;
    }
    if(h!=m)cnt--;
    cout<<cnt<<endl;
}