include

include

using namespace std;

int max_of_four(int a, int b, int c, int d){

if(a>b&&a>c&&a>d){
    return a;
}
else if(b>a&&b>c&&b>d){
    return b;

}
else if(c>a&&c>b&&c>d){
    return c;
}

else{
    return d;
}

}

int main() { int a, b, c, d; scanf("%d %d %d %d", &a, &b, &c, &d); int ans = max_of_four(a, b, c, d); printf("%d", ans);

return 0;

}