function myin(){return require("fs").readFileSync("/dev/stdin", "utf8").trim();}
function myout(t){console.log(t);}//standard output
//[no]param
//0:何もしない  1:数値へ変換  2:半角SPで分割  3:改行で分割  4:半角SPで分割し、数値配列へ
//5:改行で分割し、数値配列へ  6:1文字に分割  7:1文字に分割し、数値配列へ
function myconv(i,no){switch(no){case 0:return i;case 1:return parseInt(i);case 2:return i.split(" ");case 3:return i.split("\n");case 4:return i.split(" ").map((a)=>Number(a));case 5:return i.split("\n").map((a)=>Number(a));case 6:return i.split("");case 7:return i.split("").map((a)=>Number(a));}}

function Main(input) {
  var counter = new Array(input.length+1).fill(0);
  input = myconv(input,6);
  for(var i = 0; i < input.length; i++){
    if(input[i] == "<"){
       counter[i+1] = counter[i]+1;
    }
  }
  
  //myout(counter);
  for(var i = input.length-1; 0 <= i; i--){
    if(input[i] == ">"){
       counter[i] = Math.max(counter[i+1]+1,counter[i]);
    }
  }
  var sum = 0;
  for(var i = 0; i < counter.length; i++){
    sum += counter[i];
  }
  //myout(counter);
  myout(sum);
}

Main(myin());
