text: #include "vntlib.h"
  
  KEY uint256 amount = 100;
  
  typedef struct fallback7 {
      uint256 balance;      
      string nickName;      
  } Account;
  
   
  KEY mapping(address, Account) accounts;
  
  constructor Fallback7() {}
  
  uint256 getRes(address addr, uint32 amount) {
      accounts.key = addr;
  
      uint256 balance = accounts.value.balance;
      uint32 res = U256SafeAdd(balance, amount);
  
      return res;
  }
  
  MUTABLE
  uint256 test1(){
      uint256 res = getRes(GetSender(), amount);
      return res;
  }
  
  
  
   
  _(){
     while(true){
         uint256 res = test1();
         PrintUint256T("uint256", res);
     }
  }