```
int coinChange(vector<int>& coins, int amount) {
vector<int> dp(amount+1, amount+1);
dp[0] = 0;
for (int i = 1; i <= amount; i++) {
for (int j = 0; j < coins.size(); j++) {
if (coins[j] <= i) dp[i] = min(dp[i], dp[i - coins[j]] + 1);
}
}
return dp[amount] > amount ? -1 : dp[amount];
}
```