const input = require('fs').readFileSync('/dev/stdin', 'utf8');
const [H, M] = input.split('\n')[0].split(':').map(v => Number(v));
if (M + 5 < 60) {
  console.log(('00' + H).slice(-2) + ':' + ('00' + (M+5)).slice(-2));
} else {
  console.log(('00' + (H + 1)).slice(-2) + ':' + ('00' + (M - 60 + 5)).slice(-2));
}