const main = (inputs) => {
  var a = inputs[0].split(" ")[0]-0;
  var b = inputs[0].split(" ")[1]-0;
  var c = inputs[0].split(" ")[2]-0;
  var ans = c-(a-b);
  
  console.log(ans>0?ans:0);
}

main(require('fs').readFileSync('/dev/stdin', 'UTF-8').trim().split("\n"));
