function Main(input) {
    var data = input.split(":")

    var hh  = parseInt(data[0]);
    var mm  = parseInt(data[1]);

    justDoIt(hh,mm);
}

function justDoIt (hh,mm){
   if ( mm + 5 > 59) {
      if( hh >= 0 && hh <= 8) {
          console.log( "0" + (hh + 1) + ":0" + (mm + 5) % 60 + "\n");
      } else if ( hh == 23) {
          console.log( "00:0" + (mm + 5) % 60 + "\n"); 
      } else {
          console.log( (hh + 1) + ":0" + (mm + 5) % 60 + "\n");
      }
   } else {
       if ( hh >= 0 && hh <= 9) {
           if( (mm + 5) <= 9 ){
                console.log("0" + hh + ":0" + (mm + 5) + "\n");
            } else {
                console.log("0" + hh + ":" + (mm + 5) + "\n");
            }
       } else {
           console.log( hh + ":" + (mm + 5) + "\n");
       }
   }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));