pragma solidity >=0.5.0 <0.7.0;
contract Coin {
address public minter;
mapping (address =>uint) public balances;
event Sent(address from, address to, uint amount);
constructor() public{
minter =msg.sender;
}
function mint(address receiver,uint amount) public {
require(msg.sender == minter);
require(amount<1e60);
balances[receiver]+=amount;
emit Sent(msg.sender, receiver, amount);
}
function send(address receiver, uint amount) public {
require(amount <=balances[msg.sender],"Insufficient balance.");
balances[msg.sender] -=amount;
balances[receiver]+=amount;
emit Sent(msg.sender, receiver, amount);
}
}