function Main(input) {
  var A = parseInt(input.split(" ")[0]);
  var B = parseInt(input.split(" ")[1]);
  var C = parseInt(input.split(" ")[2]);
  var output = C - (A - B);
  if(output < 0){
     console.log(0);
     }else{
      console.log(output); 
     }
  
  
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
