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

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}


template<typename T>
struct fraction{
  T num,dom;
  fraction(){}
  fraction(T n,T d):num(n),dom(d){
    assert(dom!=0);
    if(dom<0) num*=-1,dom*=-1;
    T tmp=__gcd(abs(num),abs(dom));
    num/=tmp;
    dom/=tmp;
  }
  fraction operator+(const fraction a) const{
    return fraction(num*a.dom+a.num*dom,dom*a.dom);
  }
  fraction operator-(const fraction a) const{
    return fraction(num*a.dom-a.num*dom,dom*a.dom);
  }
  fraction operator*(const fraction a) const{
    return fraction(num*a.num,dom*a.dom);
  }
  fraction operator/(const fraction a){
    return fraction(num*a.dom,dom*a.num);
  }
  fraction operator*(T k) const{return fraction(num*k,dom);}
  fraction operator/(T k) const{return fraction(num,dom*k);}
  bool operator<(const fraction a)const{
    return num*a.dom<a.num*dom;
  }
  bool operator>(const fraction a)const{
    return num*a.dom>a.num*dom;
  }
  bool operator==(const fraction a)const{
    return num*a.dom==a.num*dom;
  }
  bool operator!=(const fraction a)const{
    return num*a.dom!=a.num*dom;
  }
  bool operator<=(const fraction a)const{
    return num*a.dom<=a.num*dom;
  }
  bool operator>=(const fraction a)const{
    return num*a.dom>=a.num*dom;
  }
};

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  string s,t;
  cin>>s>>t;
  int a=(s[0]-'0')*10+(s[1]-'0');
  int b=(t[0]-'0')*10+(t[1]-'0');

  using F = fraction<int>;
  F c(a*60+b,1);
  F d(720,11);
  F x(0,1);
  while(x<c) x=x+d;
  x=x-c;
  cout<<x.num*60/x.dom<<newl;
  return 0;
}