process.stdin.resume();
process.stdin.setEncoding('utf8');

var g_input = '';
process.stdin.on('data', function(chunk) {
    g_input += chunk;
});
process.stdin.on('end', function() {
    main(g_input.split(/\r?\n/));
});

function main(inputs) {
  var a = inputs[0].split(" ").map(function(a){return parseInt(a);});
  var X = a[0];
  var A = a[1];
  var B = a[2];
  if(B <= A){
    console.log("delicious");
  }else if(B <= A + X){
    console.log("safe");
  }else{
    console.log("dangerous");
  }
}
