// A pronic number is a number which is the product of two consecutive integers
// 42 = 6 * 7 -> yes 6 and 7 is consecutive integers
// 45 = 5 * 9 -> no 5 and 9 is not consecutive integers
  
function isPronicNumber(num) {  
    for (let i = 1; i <= num; i++) {  
        if ((i * (i + 1)) == num) {  
            return true;
        }  
    }  
    return false;  
}  
  
const num = 42;
      
if (isPronicNumber(num))  
    console.log("yes");  
else
    console.log("no");  
 
  
  
  
  
/*
run:
  
"yes"
  
*/